Snail:
• They have a shell that is adapted to protect them against predators and the elements.
• They are also adapted to hibernate, especially snails that live in areas prone to frost or freezing temperatures, during the winters. Alternatively, snails in dry, arid regions will estivate - a summer version of hibernation - when water is scare or when there are droughts.
• Snails' slime is naturally hygroscopic, meaning that, instead of releasing water, it attracts it. This helps snails stay damp throughout the day and assists in movement, reproduction and breathing.
Crabs:
• Instead of having an internal skeleton they have exoskeletons. This creates an extremely hard exterior making them more susceptible to attacks from predators.
• All crabs have eight regular legs and two specially adapted legs known as chelipeds or claws. They help them to feed and to catch prey.
• All crabs have both a set of antennae and antennules. They see through their eyes, which are located on the end of long eyestalks. The purpose of these eyestalks is to allow them a better field of vision -- they can see in front of themselves, behind themselves and to the sides -- which is an advantage when hunting or looking out for danger.
