Acorns are the key though other nuts like walnut and hickory work too. Their working is at certain times of the day , not continuous. It's funny they have a union I guess.They start a 7 am ,work for a while then take a break ,all doing it at the same time ! A good area always is except the fairly rare times when preditors take over Then there's nothing !!
But it's back in a year or two.