Not sure what's going on with the chickens this morning. They always coming running out of the henhouse when I open the door. This morning, two ran out and then right back in. They are all staying inside as though afraid to come out. There are no hawks around, it's daylight so no owls present, electric fence is on to deter foxes. Egglaying is way down, 5 eggs from 17 birds the last two days. Don't know how to read this. This is a well established flock of 18 birds ranging from 1 to 3 years old and of mixed breeds. We haven't introduced any new chickens since last spring. They have easy access to clean food and water in and out of the coup and it's not overly cold this morning. Any ideas?