Here we can see a clear example of how a tarantulas grows through molting. Many times through its life it will grow by a process called molting where it sheds its old exoskeleton. This will happen at various ranges from once a month to once a year depending on size and species. You may see your tarantula get super chubby or kick off its butt hairs (depending on species) or may even get a glossy black abdomen. After it molts it's important to be very careful as they are fragile for a few days.