What is killing my chickens

[jdherenow]

I have heavy metal floors and walls and screen under the plywood roof. There is only a little screen where the roof is connected to the walls. I've had the chickens a year and the other day one got eaten. I only found the feet. I reinforced the screen. I checked everywhere and can't find out where anything could get in. Two more dead, so today I put them in my porch for safety. I live outside Chicago on 4 acres. I have never seen a snake and have lived here for over 30 years. A large animal did not get in the coup. If something squeezed in through the screen it would have to be no bigger than a few fingers in width. What could be eating my chickens?

 

[Gargoyle]

A weasel can get in through a 1" diameter opening. I'm on a similar property to you, also in the Chicago area, we've never seen weasels here (but we do have pretty much everything else) but that doesn't mean they're not around.

What kind of screen is it? how is the screen attached? What kind of latch is on the door? Raccoons can work many kinds of latches.

BTW,

 

[jdherenow]

I looked up Weasels, and yep it could fit through the little wire openings. I am so glad you had the answer. I would have never known we even had Weasels had you not told me. I live in Wayne/St. Charles. How horrible for these darling Chickens. They are my little pets. They run to me, eat out of my hand and love being held. Oh, the door is very secure. The metal floor and walls are heavy duty steel used on Chicago construction sites along the sidewalk, attached with wire. The mesh screen is the problem. I need to work on that. Thank you sooo much.