Although tarantulas blend in with the dirt and scrub along the Mt. Diablo trails, the trained eyes of the trek guide and knowledgeable members quickly identify spiders and their burrows along the hike.
This male tarantula is one of many that leave their burrows during mating season, seeking a female tarantula. Tarantulas are not aggressive, and the venom of a tarantula is considered mild to humans -- no worse than a bee sting.
Although it's fascinating to get up close to a tarantula for a better look, one defense mechanism the tarantulas employ is rising up and emitting fine hairs toward their predators. It's a non-lethal form of defense that can temporarily put a predator off their trail. But it's best to back up if you see a tarantula engaging in this behavior.