In my state only certain animals must be killed after trapping, namely furbearing animals that are known to be common rabies vectors. Squirrels or rabbits are not included as they are game animals and the incidence of rabies in them is miniscule, since the odds of them living after an attack by a rabid cat, fox or coon are very small. However, good point, one should check with their game department to find out what the law is. I couldn't begin to give you a number of the squirrels and rabbits I relocated other than a whole lot.