There is no doubt that terrestrial snails play an important role in ecosystems. Snails eat at the bottom of the food chain. They eat rotten vegetables and wet leaves. They are also consumers of mushrooms and soil. Terrestrial snails often rely on diets rich in calcium and other nutrients to support their growth, shell repair, and general health. Also, snails are used in the feeding of many animals: Snails are food for dependent predators.

Insects, lizards, and snakes are some of the animals that eat snails. Other animals, such as fireflies, consume snails only during their larval stage. Passerines, for example, require additional calcium during the breeding season to develop eggshells and promote growth. Snails are therefore an essential source of calcium for many songbirds. More recently, however, human-induced changes have become a challenge for snail populations, and arguably a major challenge,especially for breeding birds.

Eeva, Rainio, Suominen, 2010 study on the impact of pollution on the abundance, size, diversity, and environmental science of land snails as a resource for flycatchers, had the aim to examine how the availability of land snails varies along the contamination gradient. They were able to show that total snail shell mass increased towards the source of the pollutant, but decreased sharply near thaw. This research contributes significantly to the understanding of how human pollution has affected the population size, individual quality, and ultimately the reproduction tendencies in many birds.