Tarantulas have several defense mechanisms to protect themselves from potential threats. One of the primary defense mechanisms of a tarantula is their ability to flick urticating hairs from their abdomens when they feel threatened. These barbed hairs can irritate the skin, eyes, and mucous membranes of predators or humans, causing discomfort or even pain. Additionally, tarantulas can also use their large fangs to deliver a venomous bite as a defense mechanism when necessary.