stork your first sentence is some statement, creatures fur or feather that live in citys are used to getting food from in and around man made objects, there fore become less fearfull of taking food from such places, there rural cousins are ALOT more trap shy as they dont live around human inhabitted areas as much.., yes they probably raid more nests cetainly aint easier to get into a trap..
Well i know what your saying i live in a village loads of maggys i used to worn on an estate (shooting) i had no end there i brought the trap home it took 4 days befour one went in it might be the