Mudsnails, not to be mistaken with Periwinkles, are small, black snails found in great numbers on tidal mud flats, often underwater. These snails are less than an inch in length with the spire worn down at the tip. The shell is usually covered with a slimy, green-brown growth, which camouflages it well. Mudsnails can burrow into mud to avoid drying out during low tides and to hide from their predators, which consist of fish and birds. As they travel around on the mud in search of microscopic plant life or decaying animals flesh, they will leave a small, grooved trail behind them. Mudsnails are able to detect decaying flesh from long distances by possessing a sensitive chemoreceptor sense of smell.