The Rosy Wolf Snail, also known as the Cannibal Snail, is a large member of the family Spiraxidae. It has a delicate pink shell which belies its carnivorous appetite and ruthless hunting behavior. They cruise along the ground at a speed 300% faster than other snails, searching for signs of smaller gastropods with specialized chemical receptors called oral lappets. When they detect a slime trail, the follow it until they overtake the prey snail.
Once a Wolf Snail has found its prey, it uses its unusually long neck to hold the shell in place. Then, it extends a long esophageal tube from its head and sticks it into the aperture. This tube houses a dagger-like radula, which tears off chunks of flesh and sucks it into the Wolf Snail's stomach. If a snail is too small, the Wolf Snail will swallow it whole, shell and all. It then converts the calcium and uses it to build its own shell. It has even been known to go underwater in search of pond snails.
The voracious feeding habits of Euglandina rosea make it a valuable addition to the environment: it keeps herbaceous snails in check and prevents damage to garden plants and shrubs. It is especially adept at destroying the pestilent invasive species Bradybaena similaris, which is responsible for a lot of horticultural damage along the Gulf Coast. If you see this snail, leave it alone. Do not kill it, but use it to help maintain the health and safety of your plants.
The Rosy Wolf Snail is quite common in the Southeastern United States, especially in Florida. In Texas, it can be found in dirt under a thin layer of detritus, usually underneath a short bush. They are also fond of sleeping under dead wood or ply-board. At night or after a rain, they tend to congregate in small numbers to mate. They seem to like crawling vertical surfaces, like fences or siding.
The Rosy Wolf Snail was officially described in 1821 by André Étienne d'Audebert de Férussac, a French naturalist who had fought in Napoleon's army.
In 1955, the Rosy Wolf Snail was intentionally imported to Hawaii to control the population of Giant African Land Snails (also intentionally imported). The plan backfired: instead of targeting the pests, the Wolf Snails developed an appetite for the native tree snails. This resulted in the extinction of over a hundred Hawaiian snail species. E. rosea continues to wreak havoc in Hawaii today.