Why do snails leave a trail of slime? Why do they leave this weird trail of a goo-like substance? It actually helps them move across many different surfaces so that they don't damage their skin, it also helps them to keep moist for a long period of time, as snails need to keep moist. If they dry out they die.

How big do snails get? Land snails aren't really the biggest animals you will see out in the wild. The Giant African land snail is the biggest species of land snails ini the world, measuring up to 8 inches. Marine snails though, can get huge. The Australian trumpet is the biggest marine snail in the world, measuring up to 35 inches (91 centimeters). The Florida Horse conch is also a huge snail. It measures up to 26 inches.