Interesting what critters are out there on the prowl for our chickens. Can't say that I blame them though. Chicken tastes great.
That looks to be a short-tailed weasel. They are brown in the summer and go white in the winter. In its gorgeous white winter coat it is called an 'ermine'. In their white coat they have a beautiful black tipped tail. If you look at paintings of european royalty, they wore ermine, mostly the black-tipped white tails. In the paintings they look as though they are wearing dalmation fur, but it's ermine. Pretty classy for the cousins of skunks, don't you think?
Oh, he is cussing you in weasel language. Thankfully they are not larger than they are. Imagine having their big cousin the wolverine ravaging your coops.
Considering the size of the openings in that trap, you can see how easily they can get into a chicken coop through any opening 1/2 an inch or larger.