In many salamanders, though, the legs are not strong enough to support the body weight, and the belly is dragged along on the ground. In these species, locomotion take the form of a serpentine wriggling motion, particularly if the salamander is attempting to move quickly. To jump, most salamanders use the both the rear feet and the tail to push themselves into the air. The cloaca in salamanders serves as the common exit point for the digestive, urinary and reproductive tracts. In most salamanders, the male is distinguished by a swelling of the cloacal lips.
Salamanders are unique among amphibians in practicing a form of internal fertilization.
During mating, the male deposits a packet of sperm called a spermatophore,which the female then picks up using the lips of her cloaca. This spermatophore is then stored and used to fertilize the eggs before they are laid. Thus, fertilization in salamanders is internal even though there is no direct cloacal contact. Tail Salamanders, like lizards, are capable of voluntarily shedding their tails if they are threatened, as a defense mechanism. The detached tail jumps and twitches violently due to muscle contractions, and diverts the attention of a predator long enough to allow the salamander to escape.