They do what they're told to do, they pick up what they're allowed to pick
up.

When I caught a possum in a county supplied trap, the animal control folks
said that they would come out and kill it and take the dead body. They
would not accept a trap with a live wild critter. (They supplied the traps
to capture CATS.)

So I told them to kill the animal. I was gone when they came but the
critter was gone and there was some sticky blood left on the trap.