Gunnerman,
First off, you might want to do a little investigating to see if there is enough work to support this business in your area. Then investigate a little more to find out if there is a market for your services. In other words, once you've determined that there is a need, then find out if anybody will be willing to actually PAY you.
In my area, there is PLENTY of need for this type of work but dang little pay off. Too many folks think that I'm supposed to be a free service of the county or state. They actually get mad when I tell them that I charge for my services. Less than 10 percent of my calls actually turn out to be paying jobs.
Then, there are the ones who really NEED my help but don't know it. They think they can handle the problem on their own. Examples are the ones loosing calves to coyotes who will not pay me to set up a line because they think they can just run out there and shoot the coyote and solve the whole problem. Or the guy who's trapping squirrels on his own and then hauling them a mile or so from the house and turning them loose. These fuzzy little tree rats are beating him back home but he thinks he's doing a good job.
I had a guy call me last week about squirrels in the attic. I set up a time to come out to fit his schedule but by the time I got there he had already stunk up the house with moth balls and rat poison and only wanted me to do the exclusion on the chimney, three stories up.
Then there is the guy who figures that the critter or critters I catch should be pay enough. Uh, uh... It don't work like that. In fact I charge for each critter I DO catch PLUS my initial set up fee or "service call". If I catch it, then it automatically becomes my property. If the customer wants to keep it then I'll be glad to SELL it back to him.
I don't want to discourage you but if you live in a rural area, these are the problems you're gonna face. If, however, you live in or near a metropolis area, you'll likely have plenty of paying work. I've noticed around here, the guys who do the best in this business are in or near the big cities.
I've been doing this for almost 5 years now and still keep my plumbing repair business. I love ADC work but still have to pay the bills. It's picking up a little all along as my name gets passed around but it may be 5 more years before I can retire from plumbing repair.
By all means, if the numbers bare it out, then give it a try, BUT, in the mean time, don't give up your day job.
Good luck.