The Future Is Here
We may earn a commission from links on this page

Horror of the Day: Tarantulas Migrate En Masse

We may earn a commission from links on this page.

Every day I find a new thing to hate about spiders. This particular day, I found out that horny tarantulas come out of their burrows and go walking around in packs. Sometimes they go in groups of thousands along migration routes. Are you in the middle of one of these centers of horror?

Say you settle in a new town. Perhaps it is Missouri. Perhaps it is Texas. Perhaps it is a lovely shack in wine country in California. You've settled in, have unpacked all your boxes, and are enjoying a little wine on the porch on a crisp fall day when you see a giant tarantula wandering up from under the porch. Naturally, you scream, jump on the table, and leap indoors, only to find that two more are in your house, having crawled in the through the patio door that you opened to let in the gentle breezes. You have just learned a thing or two about tarantula behavior. You go inside, pour gasoline over the house, and burn it down, checking your car for more spiders before you drive for someplace cold and wet.


This actual scenario does happen. Every fall in places like Concord, California and Warrensburg, Missouri, animal control people can expect calls from alarmed new owners who don't understand why their property is suddenly infested with giant spiders. They have to explain that it's not just the newcomer's property. It's the entire region. Tarantulas are usually shy creatures that sit back in a burrow and only venture out after dark to eat a few insects. In the fall, though, from September through November, the spiders leave their burrows and go out into the open to mate. The females are robust sorts, living twenty years and mating many times. They lay about a hundred eggs per mating season, of which, thank goodness, only about two survive to adulthood.

The males are more delicate. They live only seven years. Most of that life is spent in an eighteen inch burrow. In their last fall, they leave the burrow, go on a sex frenzy a few months long, and die. In order to mate with as many females as they can, they will walk for about fifty miles. This transfers the area's tarantula population from underground in a relatively small area (there are only so many places suitable for burrows) to mobile and spreading. For unlucky people who live, for example, at the outlet of a canyon, the entire herd of spiders moves through their towns.


Tarantulas are harmless. Their bites are nonfatal, and about as painful and inconvenient as a bee sting. Their major tactic, when spotted, is to freeze, hoping that they will be ignored. That being said, nothing so trivial as facts can alleviate the horror of a swarm of giant spiders. Some sites embrace the swarm, giving tarantula hikes and inviting arachnotourists. Still, we hope that we can be a help to anyone trying to find a bargain house in the market. Before you sign anything, ask if there is a tarantula migration on the property. If they are vague, tell the realtor that you'll only buy if they spend a day staked to the ground in the coming September. That ought to get you an honest answer.

Top Image: Dallas Krentzel

Via Desert USA, Danville Patch, and Every Trail.