I think its scent,Ted Brown worked as a rabbit catcher for the ministry of ag during the war, and my grandpa,said he was as good as they come. In the50s when i was growing up Ted used to say ,a rabbit sees more with its nose,than its eyes,if you ever set traps,try to cover your hands in a does piss,now i dont no if this is true ,but Ted thought so ,and he caught a lot of rabbits in his life,surely,if rabbits react to a snare ,a lot more would turn around at a purse net,back to trapping ,when my eldest lad and me set fen traps,i allways seem to catch more,we do it exactly the same,iset the tr