Wildlife work is three jobs in one: getting the animal out, keeping it out, and cleaning up what it left. Skipping the third is why an attic that has been cleared still smells, and why the next animal knows to try the same roofline.
Removal is by one-way door wherever the season allows it, so an adult leaves on its own and cannot return. Litters are handled by hand and reunited outside. Bats are excluded only outside the maternity window the state sets, which runs from May to August.