Chickens produce egg pallets. One egg pallet has eight "egg cartons", total of 1400 eggs in this wooden pallet. Chicken coop egg pallet spawn trigger has space what looks like for total of SIX egg pallets, that is 8400 eggs total. Once you have the egg pallet spawn point filled up, you'll get hourly (brown) notification on top right corner of the screen about no more room for egg pallets. Its recommended to get the increased pallet spawning mod, which stacks pallets three high.