I don't think it has any bearing. It is probably that they just didn't realize it was (could be) food. Like when you first give the girls a new treat. Sometimes they jump right in and gobble it up, but other times they wait to see if anyone else is going to try it first!I too found a dead mouse in the chicken run, thank goodness they didn't eat it. I assumed my silkie male killed it as he hangs out in the run a lot more than the girls. I quickly disposed of it. Kind of freak me out as well. Do you think they didn't eat it since I don't give them meat? Are they more opt to eat the mouse after experiencing raw meat? I kind of treat and feed my chickens as vegetarians. I feel the same way feeding them chicken eggs cooked, could lead them to eat their own eggs?