I read through the posts regarding mice in the nests. The mice are clearly loving the cozy nests - and have packed feathers and tons of food under the straw. We have cleaned out the nests; placed traps with peanut butter on them; and have the feed stored in a tightly closed plastic barrel. We have a cat who has lost interest in mice and would rather go after the birds. However, the mice are getting into the feed that is in the feeders for the chicks. Someone mentioned the "plaster of paris and powdered sugar trick". Can anyone tell me more about that?