"Of the numerous symbiotic relationships known from animals, few are as impressively intimate as those that occur between ants and a variety of arthropods. The trophobiotic associations, which involve the trophobiont providing nutrient-rich excretions or secretions in exchange for protection from natural enemies by the ants appear to be particularly successful, with numerous Lepidoptera, Heteroptera, as well as Sternorrhyncha and Auchenorrhyncha serving as the trophobiont." Johnson et al. (2001). The Acropyga ant with her mealybug shown here is a spectacular example of such a relationship, dating to the mid to lower middle Miocene. The extreme rarity of the fossil is highlighted by the fact that 3 specimens were recovered from approximately 30,000 pieces of Dominican amber screened by D. Grimaldi (AMNH).

The symbiosis between insects and flowering plants is represented by the Baltic amber Eocene bee with its abundance of pollen attached to leg hairs.

Parasitism, being a non-mutual form of symbiosis, is represented here by insects infested with nematodes and mites.