Earthworms do indeed have mouths. As they burrow through the soil, earthworms ingest the soil through their mouth- soil itself isn't very nutritious, but within the soil particles there are various microorganisms, bacteria and detritus that the earthworms are able to digest. Within the earthworm are two digestive structures that are used to process food: The crop (which is a food storage recepticle) and the gizzard (which is tough and muscular, and is used to grind up the soil particles). Food then passes through a short intestine (where absorption of the nutrients occurs), and out the anus