Lumbricus (Earthworm)

Earthworms remain underground during hot daylight hours and surface at night to find food that they can store in their burrows. Most of the organs including the brain and ten heart-like structures are clustered at the head-like end of the tubular body. Earthworms do not have lungs and all oxygen is received though the moist permeable skin. Although these creatures do not have eyes and cannot see, specialized organs that are sensitive to different intensities of light help them to navigate.