Like all species of tarantula, the rose hair tarantula molts to accommodate growth. Molting occurs approximately once a year, with older females slowing to one molt every other year.
As a tarantula grows, it needs to replace its exoskeleton; it accomplishes this through molting. During molting the tarantula casts off the old exoskeleton and replaces it with a new one. In the weeks prior to molting, as the new exoskeleton grows in beneath the old, a tarantula becomes lethargic and slow and often refuses food. Rose hair tarantulas are notorious for refusing food for months at a time prior to molting. While this is disconcerting behavior in a pet tarantula, it is a normal part of the feeding cycle. During molting most tarantulas lay on their backs with their legs in the air. The animal isn't dead or ill and must be left alone during this time. The old exoskeleton splits open along the spider's back, and the animal gently eases itself out, much like a hand sliding out of a glove. The new exoskeleton is very soft and requires time to harden. Provide a pet tarantula with plenty of fresh water after it molts, but don't feed it for at least three days; crickets can injure a tarantula with a fresh exoskeleton.