Tarantulas are often misunderstood, leading many to wonder if they bite humans and what the consequences are. Understanding their behavior and defense mechanisms clarifies potential interactions.
Do Tarantulas Bite Humans?
Tarantulas can bite humans, but only as a defensive response. They are not aggressive and typically bite when threatened, provoked, or handled carelessly. Their natural instinct is to retreat. Not all tarantulas bite with the same likelihood or venom potency; some are more docile, others more defensive. A bite is usually a last resort after other defenses, like flicking hairs, fail.
Understanding a Tarantula Bite
A tarantula bite is painful, often compared to a bee or wasp sting. It causes sharp, stinging pain at the site, which can throb and persist for several hours.
The bite area may become red and swell. Most tarantula venom, especially from North American species, is not dangerous to humans. Rarely, mild systemic effects like nausea, muscle cramps, or fatigue may occur. The venom contains chemicals that can affect nerve signals or break down tissue, but severe effects are uncommon.
Severity of Tarantula Bites
Bites from many common tarantula species, especially New World pets, are not medically significant. They typically require only basic first aid, like washing the area and applying a cool compress. However, secondary bacterial infections can occur if the wound is not cleaned.
A more serious concern is the possibility of an allergic reaction, including anaphylaxis, in susceptible individuals. Severe allergic symptoms include difficulty breathing, rapid heart rate, or a drop in blood pressure, requiring immediate medical attention. Old World tarantulas (Asia, Africa) have more potent venom, causing intense pain, muscle spasms, and lightheadedness, though bites are typically not fatal.
Urticating Hairs: Another Defense
Many tarantulas, especially New World species, use urticating hairs as a defense. These barbed bristles on their abdomen can be kicked off when threatened. They are designed to irritate predators and can be uncomfortable for humans.
Contact with urticating hairs causes intense itching, rash, redness, and skin irritation. If hairs enter eyes or airways, they can cause significant irritation, including temporary blindness or difficulty breathing. Reactions can be more prolonged than a mild bite. If exposed, avoid rubbing, wash gently with soap and water, and seek medical attention if irritation is severe or affects sensitive areas.
Preventing Encounters
Minimizing the risk of tarantula bites or urticating hair exposure requires understanding their behaviors and taking precautions. In common areas, knowing their habitats like burrows, logs, and rocky crevices helps avoid accidental encounters. Wearing gloves when gardening or moving outdoor debris provides protection.
Shaking out shoes and clothing before putting them on is a practical measure in tarantula-prone regions. Avoiding direct handling of wild tarantulas is recommended, as bites often result from feeling threatened. For pet owners, secure enclosures and safe handling, or avoiding handling, can prevent incidents.