A myrmecophile is an animal that lives with ants. A myrmecophile may help the ants, or it may be a parasite of the ants by eating them or their food.
Many myrmecophiles eat waste in ant nests, such as dead ants or fungi growing in the nest. Some myrmecophiles make food that the ants can eat. Aphids do this when they make honeydew. Ants may even farm or tend some insects, such as aphids, that make food for them. Other myrmecophiles eat the food supplies of ants, and a few eat ant eggs, larvae, or pupae.
One family (group) of butterflies lives with ants and sometimes makes food for the ants. The ants help the butterfly caterpillars by keeping away other animals that want to eat or hurt the caterpillars.
Other animals that live with ants include some beetles, flies, mites, and spiders. Flies in the genus (group) called Microdon live in ant nests and eat waste or eat larval ants.