I built cages for our blueberries which seemed to work well until a catbird managed to get in, how I couldn't figure out. After freeing him, later on there were TWO catbirds in the cage feasting. I freed them and saw the lid covered with bird netting had a hole in it which I fixed. Later on I watched from a distance and saw them standing on the lid and pecking and pulling on that netting tryiing to make another hole. So now the cages are covered also with Remay and if that doesn't work- bring on the electricity!!! :P