The term “slug” is a catch-all for any land-based gastropod mollusc that doesn’t appear to have a shell. This stipulation came about becomes some species have small vestigial shells inside them. Infamous as garden pest, slugs have been maimed, hunted and tortured – often unnecessarily.
Compared to the previously persecuted house sparrow or the many species of birds of prey which are now subject to protections and organisations set up to enable their survival. The underappreciated and often-hated slug is regularly killed en masse, with dire effects throughout the food chain.
However, the slug’s delicate system shows a mastery of evolution.
Moving in rhythmic waves, it contracts the muscles on the underside of its foot while a layer of mucus is produced to smooth the slug’s path across the ground. This mucus is also used as the slug’s navigation system, as slugs will find their way back to their burrows and feeding sites by following their own mucus trails.
Mating is a spectacle to behold, as slugs are hermaphroditic. Once two individuals have located each other, they embrace in a slimy, oozing mass.
Encircling each other’s bodies and gliding together. An exchange of sperm takes place from protruding genitalia and, finally, once the deed is done; both parties slowly slither away.