In southern michigan. I have customers that I belive still have bat activity. When do bats stop going out and coming in

If they are wintering in a site they can fly off and on through out winter. We have Big Brown Bats that I have witnessed flight in Dec. and Jan. over the years when the temps warm to unseasonable norms for several days.

They will fly in some cold temps but probably not much to eat out in those temps.

Also have had flight in homes off and on thru the winter months quite often.

Really hard to say when they stop all flight in these parts due to the fluctuating temperatures that we experience.

I am not familiar with the seasonable temperatures in your region but just about when you say it never happens after a certain date it does. So I would remain cautious with discounting the possibility. I would think it is more common then many realize.

If you don't have much experience with the species I can see why some would not think like I do.

Not discounting it at all, descriptions of the sounds I'm given from some clients make me believe they have bats moving in the attics and some walls.

Of course as we all know, the clients say. It moves to fast or is to loud to be something small like bats or mice

Many many folks like bob said who have witnessed winter activity
for a long Long time. No hard and fast with their behavior.

Researchers that publish tracking data also show winter movement
not only cave to cave, but just basic outflights and returns.

Many NWCOs and Rehabber and others will get calls mid winter for bats who show
up inside.

My only real .02 for you and it’s something Ron Scheller has said before on here
and others have is that if you are doing normal exclusion where you are adding one
way devices and sealing the rest of the home an you don’t have emergence happening,
you run the risk of entombing the bats when you return 10-14 days after initial work and remove
the one ways and finish sealing.

Since bats can overwinter in structures you have to be careful to not to too late.

The other thing some do is leave tubes on all winter. This has the potential to have bats exit
who plan to overwinter under attic insulation and return to be locked out when temps are too low.

I believe and maybe he’s lurking or others who use this method can comment, but some folks take
The deposit, start the sealing process leaving open just necessary entry and exit points so bats aren’t entombed
and are not locked out when too cold.

Then return in spring and complete the work when bats become active again and before maternity season.

There are good criteria out there, but each company tends to decide still for themselves unless their state
mandates it.

I’ve got bats in my mountain areas that are still there though it’s alreasy snowing and dropping I into teens at
night.

I stop venting and excluding when too cold based on my survey work, our home and commercial and bridge work
And other ways we see bats on the job.

I’d caution anyone who isn’t legally mandated to stop at a certain temp or point from just excluding well into winter with
no notion of death and mortality in bats that is possible.

I have species that generally migrate out of the country and every winter I get rehab intakes from downtown when it’s mid January and
17 degrees.

Just .02. National AMPs talk about not excluding below a certain temp for X number of days in a row.

I usually go by the flying insects. When the food is gone the bats are using as little of the fat reserves as possible.

As I suspected it there may be bat activity in attics and walls I still put a trail camera on an opening and was surprised to see bats coming out of the house with a temperature reading if only 33 degrees


Thanks for your input

Good confirmation of the activity MI trapping.

Definitely doesn’t indicate a good time for exclusion though.

When so many roosts can’t be completely viewed due to location, some
bats in the colony may be dormant while your seeing the others emerging.

When you are around freezing you are prone to entombing with exclusion
going on.

You didn’t state if you are going to go ahead with exclusion, so have to assume
but hope you can educate the client on the potential to entomb and cause mortality
to the bats as well as potential decomp odors for the owner and increased likelihood of
bats coming out inside the home when they awake to find they can’t leave through the
previous exits.

I’ve yet to have a client who wasn’t willing to work within everything avoiding those issues
when explained to them.

No plans to exclude them till spring, i was surprised to see them exiting when it was so cold outside

I know better than to seal bats in

Thanks for clarifying MI Trappin.

Appreciate it! We don’t know each other as many of us
don’t so when I’m posting it’s with the idea of anyone who
my be reading.

When folks are newly working with bats the dollars in hand
can quickly override the best judgement sadly see this plenty
just in my area and a quick FB search on “by removal” during
times like maternity season shows folks even in states with laws
performing exclusion and grabbing pups and lactating females with
pliers and saying they are “relocating” the colony.

Glad your one of the ones doing it right and will always assume that
when you are talking bats or asking in the future.

Best,

Justin

Basically when nighttime temps are consistently below 50F, and when the flying insects go away, you stop.

as i understand it...Illinois changed law this year that bat exclusions cannot be done once temps are under 50 degrees

Illinois new law went into effect June 28,2017. Permanent eviction of bats may be performed from
1 March 15 through May 15. When outdoor temperatures exceed 50 degrees F at dusk.
2 August 5 through October 30 when outdoor temperatures exceed 50 degrees F. at dusk and the permittee has made a reasonable attempt to determine young are capable of flight.
word for word out of Illinois new laws.

So Illinois made a law that says "if you have a health risk in your home you can only remove it during those said time periods"

IMHO ridiculous to make it a law, guideline yes , law. Should not be, now bats life is more important than human life.

MI Trapping,

I haven't seen the way the new law is written, but we already have "wildlife laws" like this in many states for maternity season (the blackout period), where
as NWCO's we are supposed to wait.

Generally speaking there are exemptions that can be achieved when there is a true threat to human health and safety.

That includes during maternity season which has been an issue far longer than the notion of late fall/winter entrapment and issues.

The goal behind these laws is to get folks like in your scenario of the original post you put up, to think about the issues of entombing bats who are in the
exterior, but not emerging regularly, or may be frozen out.

With maternity season of course, the goal is to encourage people to do the right thing and wait till pups are able to fly and leave with females before
excluding.

Ultimately many many companies and fly by nights we will never hear about are excluding right through all seasons, this is factual and yes every industry
has people doing things that aren't acceptable or standard or even legal.

When bats are in the exterior and even the attic of a home, people can argue the human health and safety aspect and try to push for exemptions to get
the bats out, they may even take matters into their own hands if they don't get these exemptions and the bats end up dead.

If bats are entering the living quarters during summer maternity or winter / hibernation times via holes, penetrations or other in the interior of the home, it is
often possible to do an interior seal to allow the bats to stay where they are and keep the people out of potential of grabbing or handling bats causing an exposure.

Every year I get about a dozen cases during maternity season mostly cabins and mountain homes where people have had a few bats get inside and they need exclusion.

Every case has been resolved with an interior seal and most are solved in the case of the prime architecture of log cabins by sealing along the main purlin in the great
room which isn't sealed well to the trim boards or tongue and groove ceiling. The folks enjoyed the rest of the summer until August 15th and then we went and excluded.

I have charged for interior seal, but usually anymore I just tie it in with exterior sealing and for us it is a conservation tool to get people to wait till appropriate time without
worry for their family having to deal with live bats in the living space.

Every client is different of course as we all know, but if bats are in the exterior only or well separated attic and the client only knows they are there because they've seen them
emerge from the exterior, or they hear them in the walls but no live bats have ever been inside the house or found dead inside the house, the human health and safety risk is
considerably lower unless they try to go into those areas and extract the bats manually themselves and end up grabbing them with bare hands, etc..

*****

But, to your statement, I do not know of a single state where ultimately if people are ending up with live bats in exposure scenarios fit CDC's list where exclusion won't be allowed.

No one I've ever met in govt. employment wants to open their office up to liability, this is about trying to encourage people to find ways to do exclusion at the right time of year
and to not persecute or put bat populations in jeopardy, while maintaining public safety in terms of potential exposure.

So yes it would sound ridiculous if we think every bat colony is a rabies exposure issue for the owner of the structure, however they are not, some will be, some won't and even those
who are can be often mitigate from the interior until proper season is reached unless the home or structure is in rough shape or in the middle of renovation, etc...

Improving bat conservation on the books is never discussed in any working group I've been to as a way to increase exposure of people to live bats, people always accept in these groups
that there are cases where something will need to be done, or you risk people handling bats or becoming exposed and this is always a black eye in the media who tend to write the biggest
headline to sell papers and therefore malign bats further.

It is important though that we accept that bats can get rabies, but they are the lowest prevalence rabies vector in North America. The science behind bats and rabies shows less than 1% and even
1/2 of 1% in wild caught and tested bats. Papers and the health department report on rabies from a skewed portion of the population, found down, found within grasp of people, etc... The national reporting also doesn't usually look at species either, or the fact that bats live in colonies or solitarily, or their behavior. So they can report "rabies is on the rise in bats" while we should be asking, "which bats
from what colony? What species? Which location? "

We need the public to all know don't touch or handle bats, and we'd see far far less reports of any exposure out there.

You stated twice "to encourage" and once "to make them think about"

That is educational not law

I'm 100% for leaving them alone and doing the right thing, but to make a law that says you can't exclude or remove is not educating or promoting it is legislating and adding criminality

That's what I'm saying, and I agree that the rabies scare is far over blown, but if a large colony exists and there are individuals with compromised immune systems that is a health risk

In the fall of 2016 I had a call for bats where a ceiling had been removed and bats were discovered, my first call was to the MDNR office that issues and is responsible for nuisance wildlife permits and oversees or work

Right from the head persons mouth to my ear, " we would like you to extract them alive, but if they are in the home, no one is required to live with a potential health hazard"

That's encouraging me to do the right thing (which I did) not making it a crime or civil infraction to do what needed to be done

As you stated for your self, I have not read the Illinois law either, I'm just questioning making I a law vs. Educating people

Illegal to molest, kill or destroy them in the wild, ie; a tree cavity, cave, ect makes perfect sense to me, but in a dwelling or otherwise occupied building like a school, church, hospital, ect I just don't think it is right to make it a legal issue

JMO

Definitely a good dialogue MI Trappin and a good story about the bats in the ceiling renovation.

We are on the same page overall on this, wildlife laws are often created and often broken and of course
seldom enforced unless caught in the act which makes them somewhat useless seeming or over reaching sometimes
unless we are talking poaching, etc...

Several of the workshops I've been to for white-nose syndrome have state game and fish folks along with feds of course
from those same regions or areas. Often they discuss these possible restrictions and ultimately when it comes to houses
or human occupied structure most are logical in thinking "we don't want folks unable to evict bats from their home if there is
a safety issue." This does have issues of course if a law is made because it creeps closer to needing a permit for each and every
house you exclude and most states wouldn't have the labor for that in house or it would slow or complicate things to the point
where homeowners would likely be taking matters into their own hands or suing.

****

Folks like yourself who make the call to the DNR to see what to do and are lucky enough to get someone who said what that one did
are rare I think. I live in a state with far less people and most are condensed into 3 primary cities. Every year I'm amazed and often appalled
at the stories that I get not only from in state that I often see with my own eyes, but from colleagues across the country.

Even in our area which I'd call a small pond for nuisance wildlife compared to the midwest and other areas well occupied by companies, we have
many folks attempting all manner of wildlife even if they need a permit and didn't get one many have done the same work for 10-20 years and didn't
know the game dept. requires one for protected (regulated harvest) furbearer here.

Too many colleagues have stories both from our industry and from game and fish personnel who get called by homeowners to come look at the bat issue
after something was done by a company or individual claiming to do it right.

I think some states want to assure they can prosecute for intentional harm, notwithstanding our agreement that it makes it hard for folks if they do or feel
they do have a disease risk.

Sadly there are enough folks who are looking for a company to handle wildlife issues that even if someone gets dinged or caught, they are likely still out there
doing it to someone else in the same community.

Definitely a slippery slope with trying to create change via regulation, but in non formal or standardized states, where there isn't a permit to work with bats for
example, I think they struggle with how to get to the audience to pass on what they'd like them to do, ie, don't exclude below 50 degrees.

Personally I know the 50 degree mark comes from a lot of discussion and deliberation from many inputs, but as has been stated, they are often active far lower.
In rehab even in 65-70 degrees some bats like silver-haired for example can go 5-7 days without eating, used to make us worried they weren't doing well, but with
years now under our belts and dozens of them coming through our hands we've learned they can enter torpor and basically not want any food or even water during
a period of that length.

Have also had bats where a large attic well established colony wasn't there yet in the spring, nights were very very cold when looking at nighttime lows. But suddenly even
with the cold nights, they showed up several thousand all at once. This made me start looking at sunset to midnight for temps and while bats can fly at the lower temps, I
believe based on my area and what I've watched that they are taking advantage of the time when its warmest, insect availability should be optimal and then roosting once
the true night lows are reached.

When we release rehab bats we do try to follow the 50 degree rule and it can still take 10-20 minutes before they completely come out of torpor from riding back to where they
were injured or found and being ready to fly (species dependent, some take forever, some are quicker).

Good discusion though, appreciate your taking the time and also your bat ethic. I think most who work with bats for any length of time view them different than other species we work
with, I sure didn't grow up a bat fan by any means, was only taught rabies and zero in terms of any benefits or their role in the natural world. Now we do our best to do outreach all
the time whenever folks want it. Have a grant with a local soil and water where we do all the 3rd grade classes each year presentation with video and pics biology, behavior, etc.. and they get
to view (not touch) live native bats. All together its about 700 kids we get to teach to not pick up or handle bats and help educate on the good stuff while talking about all the important
safety things too. Have 25 classes in December and the rest in Jan and Feb.

On a local note, 15+ years ago when we lived in northern MI we had a colony of little brown bats in the attic of the place we rented out in the woods. Had one enter the house one night and fly around
while sleeping, wife woke me up quietly and said, "theres a bat flying around" to which I responded like we had a group of armed intruders in the living room! Have calmed myself since then and I tell that story to all adult groups we speak to just so they know I wasn't always a "bat guy."

Appreciate the dialogue,

Justin

FYI.... Anyone who uses a calendar (or bat study information that was published 60 years ago) to claim when bats are hibernating is missing out on reality. Bats will often go into (and come out of) hibernation many times during the winter, especially in late fall or early winter. I was out working on my new trap storage building tonight (after dark) and there were bats out feeding on moths (and probably other insects).... yes, on December 3rd. They respond to temperatures, not calendars. My phone has been ringing off the wall (bat calls) for a week due to very warm temps. Can't really do anything at this point other than internal seal-ups, especially since the new laws in Illinois have a cut-off date of October 30 for eviction devices. That's a whole other subject, and I was invited to the meeting a couple years ago when DNR started working on bat regs. I'd share some of the exchanges we had in that discussion, but would take 4 pages of typing.

Some excellent info in this post. Justin if you ever make it over to the eastern side of the country for a class or conference I’d love to sit down and have a conversation with you. Think it’s great how much passion you have for your work and bats as a whole! Just my two sense have a great holiday folks!