If the snail suffers a cracked shell due to being dropped or falling onto a hard surface it is likely that it will survive, if given the right conditions. It is important that a snail with such an injury is NOT handled, except to replace it in the tank. Food and cuttlebone must be made readily available and the snail must be misted with clean water more regularly as there is a risk of the snail losing moisture through the crack and therefore becoming dehydrated. If the tank is particularly over-crowded or is in need of cleaning out it may be more beneficial to the injured snail to be placed instead in a seperate container with clean, fresh substrate. This minimises the risk of other snails disturbing the shell and potentially making the injury worse, and minimises the risk of infection getting into the site of the injury. Left to its own devices the crack may well heal sufficiently that it will not be a problem for the snail, although once a snail has suffered this type of injury it must be remembered that the shell will not be as strong or tough and further potential injury should be avoided at all costs.