10 Fascinating Facts About Tarantulas

Why Tarantulas Should Inspire Fascination, Not Fear

Tarantula
Kendall McMinimy / Photographer's Choice / Getty Images

Most people flinch in horror at the sight of a tarantula. These big, beefy spiders strike fear in the hearts of arachnophobes everywhere, but tarantulas are some of the least aggressive and dangerous spiders around. These 10 fascinating facts about tarantulas will give you new respect for this amazing arachnid.

1. Female tarantulas can live 30 years or longer in the wild

Female tarantulas are famously long-lived.

Even in captivity, they've been known to live for over 20 years. Males, on the other hand, don't make it much beyond reaching sexual maturity, with a life span of just 5-10 years on average. In fact, males don't even molt once they reach maturity.

2. The largest tarantulas have a leg span the size of a dinner plate

Even spider lovers might have trouble sitting still with a 10-inch tarantula headed toward them. The South American Goliath birdeater tarantula (Theraphosa blondi) is the largest spider in the world. Movie directors love to feature tarantulas in their horror flicks, which has given these big, fuzzy spiders an undeserved bad rap.

3. Tarantulas are quite docile and rarely bite people

Many large predators would quickly make a meal of a tarantula, so they aren't too anxious to tangle with something as large as a person. And it wouldn't do a tarantula much good defensively to bite you, since its venom doesn't pack much of a punch.

A tarantula bite is no worse than a bee sting in terms of toxicity.

4. Tarantulas defend themselves by throwing needle-like hairs at their attackers

If a tarantula does feel threatened, it uses its hind legs to scrape barbed hairs from its abdomen and flings them in the direction of the threat. You'll know it if they hit you, too, because they cause a nasty, irritating rash.

Some people may even suffer a serious allergic reaction as a result. The tarantula pays a price, too – it winds up with a noticeable bald spot on its belly.

5. Tarantulas ambush small prey at night

Tarantulas don't use webs to capture prey, they do it the hard way – hunting on foot. These stealthy hunters sneak up on their prey in the dark of night. Smaller tarantulas eat insects, while some of the larger species will hunt frogs, mice, and even birds. Like other spiders, tarantulas paralyze their prey with venom, then use digestive enzymes to turn the meal into a soupy liquid.

6. A fall can be fatal to a tarantula

Tarantulas are rather thin-skinned creatures, particularly around the abdomen. Even a fall from a short height can cause a deadly rupture of the tarantula's exoskeleton. For this reason, handling a tarantula is never recommended. It's easy to get spooked, or even more likely, for the tarantula to get spooked. What would you do if a huge, hairy spider started squirming in your hand? You'd probably drop it, and quickly.

7. Tarantulas have retractable claws on each leg, like cats

Since falls can be so dangerous for tarantulas, it's important for them to get a good grip when climbing.

Though most tarantulas tend to stay on the ground, they sometimes climb trees or other objects. By extending special claws at the end of each leg, a tarantula can get a better grasp of whatever surface it is attempting to scale.

8. Though tarantulas don't spin webs, they do use silk

Like all spiders, tarantulas produce silk, and they put this resource to use in clever ways. Females use silk to decorate the interiors of their burrows, which is thought to strengthen the earthen walls. Males weave a silken mat on which to lay their sperm. Females encase their eggs in a silken cocoon. Tarantulas also use silk trap lines near their burrows to alert them to potential prey, or to the approach of predators. Scientists recently discovered tarantulas can produce silk with their feet, in addition to using spinnerets as other spiders do.

9. Most tarantulas wander during the summer months

During the warmest months of the year, sexually mature males begin their quest to find a mate. Most tarantula encounters occur during this period, when males disregard their own safety and wander during daylight hours. Should he find a burrowing female, he'll tap the ground with his legs, politely announcing his presence. The courtship is quick, with the male quickly handing over his sperm and trying to escape. To the female, this suitor is a good source of much-needed protein; she'll often try to eat him once their marriage is consummated.

10. Tarantulas can regenerate lost legs

Because tarantulas molt throughout their lives, replacing their exoskeletons as they grow, they have the ability to repair any damage they've sustained. Should a tarantula lose a leg, a new one will reappear as if by magic the next time it molts. Depending on the tarantula's age and the length of time before its next molt, the regenerated leg may not be quite as long as the one it lost. However, over successive molts the leg will gradually get longer until it reaches normal size again. Tarantulas will sometimes eat their detached legs as a way to recycle the protein.