However, although the queen never has to leave the nest except in emergencies, ants are cold-blooded and have to take care in regulating their temperature. The queen is moved up and down a vertical shaft of the colony as temperature and humidity fluctuate. These shafts extend three feet or more into the ground, so a queen near the bottom of the shaft would be difficult to reach. The best time to apply these insecticides to mounds is mid-morning on sunny days after a cool night because ants, including the queen, are warming themselves near the top of the mound at such times. Unlike contact poisons, stomach insecticides are fatal only after eaten.
Fire ants have an amazing defense system against stomach poisoning.
Only the oldest, and thus most expendable, worker ants leave the nest to take on the dangerous task of foraging for food. Workers can eat liquid food when they are outside the nest, but they cannot swallow solids. So, they chew solids into small pieces and bring these to the larvae that excrete enzymes to digest the food externally. The older larvae and some workers eat the liquid portions of this food. The larvae regurgitate much of what they eat in order to feed it to the workers.