Earthworms do not have eyes but do possess light-and-touch-sensitive organs (receptor cells) to distinguish differences in light intensity and to feel vibrations in the ground.

An earthworm has five pairs of hearts, located in segments 7 through 11.

Earthworms are hermaphroditic, meaning that they possess both sets of sex organs.  However, they still need to mate with another worm to produce offspring.

The mainstay of food for robins is earthworms which they find by sight.  The robin cocks its head while hunting worms, thus leading people to believe they are listening for worms.