Nudibranchs leave a trail in their wake, just like the land snails we are familiar with. This trail is laden with chemicals and is quite expressive. It can assist a potential partner identify it or warn other nudibranchs of risks in the area!

Nudibranchs can discriminate between the chemical elements that are present in the water thanks to their sense organs, called rhinophores, and they can also detect prospective food sources from a distance.

Many nudi's consume hazardous animals and, as a clever protection mechanism, store the toxins in specialized cells.