Tarantulas can indeed bite humans, though bites are uncommon and typically occur only when the tarantula feels threatened or provoked. Understanding their defense mechanisms, including both bites and the release of urticating hairs, is important.
Understanding Tarantula Bites
Tarantulas primarily bite as a defensive measure, not out of aggression. They usually exhibit warning behaviors, such as raising their front legs in a threat pose, before resorting to a bite. If these warnings are ignored, a tarantula may use its fangs, which work like hypodermic needles, to inject venom. The venom of most tarantulas, especially those native to North America, is generally considered mild and not medically significant, with effects typically localized and not life-threatening. Some Old World tarantula species, found in regions like Africa and Asia, are believed to possess more potent venom, though scientific evidence for this is largely anecdotal.
What to Expect After a Bite
Should a tarantula bite occur, the initial sensation is often described as similar to a bee sting. The bite area may become warm, red, and swollen. While rare, some individuals might experience additional symptoms such as muscle cramping, nausea, or sweating. Allergic reactions are possible, similar to bee stings. Symptoms of a severe allergic reaction can include difficulty breathing, widespread rash, eyelid puffiness, or a rapid heart rate, requiring immediate medical attention. For a typical bite, first aid involves washing the area with soap and water, applying a cold compress to reduce swelling and pain, and elevating the affected limb. Over-the-counter pain relievers can help manage discomfort.
Tarantula Urticating Hairs
Beyond biting, many New World tarantulas possess another defense mechanism: urticating hairs. These are tiny, barbed bristles located primarily on their abdomen. When threatened, a tarantula can use its hind legs to rub against its abdomen, effectively kicking a cloud of these hairs into the air towards a perceived threat. These hairs can also be deposited around burrows or on egg sacs as a passive deterrent.
Upon contact, urticating hairs can embed themselves in human skin, eyes, or mucous membranes. Common symptoms include intense itching, a rash, and redness. If hairs enter the eyes, they can lead to irritation, inflammation, and light sensitivity.
Inhaling these hairs can result in respiratory irritation, causing coughing or shortness of breath. The discomfort can last for days or weeks, and repeated exposure may worsen reactions. Removing the hairs with adhesive tape and washing the affected area with soap and water can help, along with anti-itch creams or oral antihistamines.
Minimizing Interaction Risk
To minimize the risk of tarantula bites or urticating hair exposure, observe wild tarantulas from a safe distance. Do not handle wild specimens.
For pet tarantula owners, responsible care is important. Handling should be limited and gentle, as stress can lead to defensive behaviors. Using long tongs for enclosure maintenance helps maintain distance. Wearing gloves and eye protection is recommended, particularly when handling species known to readily kick hairs. Avoiding sudden movements or breathing directly on the tarantula prevents startling it.