When you see a snail, the first thing you see isn't his mouth -- it's likely you're too distracted by the shell. But snails are efficient eaters, with mouths located near the tentacles at the front of their bodies. If you look closely at the underside of a snail, you can see his mouth openings, and he might decide to give you a gentle taste with his rough tongue.
What They Eat
Snail mouths are specially designed to eat their preferred food: vegetation. They aren't picky, eating anything from grasses to leaves to flowers. However, they also eat limestone to ingest calcium for shell building, and some won't pass up an easy meal of meat or animal droppings. In large numbers, snails can decimate crops by feeding on fresh shoots and ripe fruit.
How to Find the Mouth
When you see a snail from the top, you see two to four tentacles sticking out from the front of his head. The longest two have eyes on the ends and some smelling ability, and if he has two more shorter ones that point downward, he uses these for smelling and tasting. If you pick up the snail and look on the bottom just under the tentacles, you'll find his mouth. Snails have small, ridged lips that open and close to allow the tongue to come out and food to go in as necessary.
Tongue Instead of Teeth
While snails don't have teeth in the traditional sense, they have a special type of tongue that's covered in ridges instead. This tongue, or radula, can have more than 2,500 ridges. To eat, the snail opens his mouth and rubs his tongue against the food source, cutting of tiny pieces with his tongue ridges. As he retracts his tongue, he brings the food back into the mouth to eat, then repeats the process.
Sharks of the Garden
Because the tongue does the hard work of cutting up the food, it gets ground down rather quickly. It grows from the back of the mouth, pushing new "teeth" forward to replace the ones that wear off the end of the tongue. This works similar to the way a shark replaces his teeth continually, although instead of losing individual teeth, the front of a snail's tongue wears away through normal use.