sorry i can't use the "bug" to report because my flash player is too old. but i want to let you know anyway.
was in my house and went to one of my chickens to incubate an egg. the chicken startled when i got close. i was still able to request incubation. the chicken landed on a ladder and made one of their usual incubating statements. seconds later the chicken flew down and walked around like normal, no "nesting". i walked over (even though I knew there had not been enough time for incubation) and sure enough no caterpillar.