The intertidal zone is a complex system with a variety of producers and consumers. Many organisms of the Intertidal Zone have adaptations that suit them well for the zone's unique conditions. Arthropods and mollusks have had great success in this zone due to their protective shells. Plants and animals found here can usually resist drying out and are able to survive freezing. Almost all creatures have some form of attachment to help them maintain their position on the shore; some hide under rocks and in grooves in the rocks to avoid being washed away. Many of the invertebrates of the zone are osmoconformers; this means the environmental salt concentration is similar to that within their bodies (so they don't waste energy trying to regulate body salt concentration). Despite the harshness of the intertidal zone there are many good reasons for living there.