Fire Ant Eggs are a resource obtained as a 1% drop from Fire Worker Ants or from Fire Ant Queen offerings. Currently it has no use but collecting these eggs and dropping them near other insects can cause them to fight so you can get a bunch of fire ant parts and have killed or kill a weakened other creature.
When a Fire Ant Egg is created, it will have a timer with 3 segments. Each segment represents 8 in-game hours. The eggs timers starts with one segment already filled, leaving 16 hours. Regardless of if it is on the ground or in an inventory, once the timer has finished, the egg will be destroyed and a Fire Worker Ant or Fire Soldier Ant will be spawned from it.