In addition to the estimated 3600 species of insects found in the park, there are many more species of non-insect arthropods, such as spiders, scorpions, and millipedes. Watching these animals can be just as interesting as observing larger animals, and these are far more common.
Tarantulas are large, furry spiders that range from light brown to almost black in color.
While you can see them during any warm time of the year here, they are most commonly seen during their mating season, from September through early November. During these months the males roam long distances searching for mates, and Big Bend s roads are literally crawling with tarantulas. Tarantulas have large fangs and can bite people, but they are not poisonous to humans. When threatened, these spiders may rear back on their hind legs, displaying their fangs, or will more commonly brush fine hairs off their abdomen with the hind legs, sending a small cloud of irritating hairs into an attacker's face. Please use caution to avoid driving over tarantulas, and remember that they are protected from harassment and collection like all other park wildlife.