Despite the fact that slugs have eyes, they cannot see shapes or colors, according to The Daily Mail. They can see shades of light, which is helpful since they are nocturnal animals. These gastropods feed at night or on overcast days.
Slugs and snails both have eyes that are located on the ends of their tentacles. They also have a defined mouth that hides a radula, or horn, that is used to collect food, according to the University of Vermont. Instead of a nose, slugs that live on the land have a breathing pore to help with respiration. The main visible difference between slugs and snails is that slugs lack a hard shell. There are species of sea slugs as well as those that can be found on land.
A species of sea slug found in the Great Barrier Reef uses eyes as a part of the mating process. This slug has a hypodermic device that it uses to stab a potential mate between the eyes, according to National Geographic. Slugs are hermaphrodites, so each of this type of creature is capable of producing a romantic stab for potential partners.Learn more about Slugs & Snails