Sleep-like states occur in the life of almost every animal studied. While the function of waking is obvious, the function of sleep is unknown. Sleep has been suggested to serve a restorative function in the nervous system. Our lab is trying to understand the function and regulation of sleep by studying different model organisms. We have started our studies by looking at a developmentally regulated sleep-like state in the larva of the nematode Caenorhabditis elegans.