Preferably...I like to use tubes in the eviction of bats..Mostly old caulk tubes because of it's 2 inch opening. I also have used the protective casing for florecent bulbs...Question is : Do you guy's that do bat work and do use the protective bulb casing , find it large enough in circumfrence seeing it is not as large as a 2 inch tube ? And of course were mainly speaking of Big and Little Browns.

I also use 1 1/2" electrical schedule 40 pvc pipe. I also use the connectors and a locknut to attach to soffits... The conduit can be bent into some funny locations

Connecter and locknut....Nice ! ..Well i know they definetly fit through the 1 1/2 , I was just kinda curious on wether or not the smaller diameter would cause any significant backflow backlashes..I guess not..Thanks

If you practice a little bit you can get a heat gun and bend the conduit in any direction that you may need. You need to practice because if you get the pvc too hot you can distort the inner diameter. In addition to that you need to practice making radius's Ie...90 degree, 45 degree and so on...just make sure that if you are creating a hole in a vertical plane (side of a house) turn the end of the conduit down and us netting or plastic so that they cannot return through the hole. You can pretty much use 2" conduit if you want to but I have found that 1 1/2" works fine. I love bat work it's kinda like bee work...If you don't seal up ALL of the holes they will be back!!!!
P.S. you can make custom parts such as drilling the appropriate sized hole in sheet metal...attach a connector...attach a lock nut...Attach the sheetmetal to an existing hole with screws...instant pvc bat nose cone....