Webjul 30, 2021 · spider bites are usually harmless, and spiders don't usually bite unless threatened. Spider bites can cause redness, pain and swelling, or you might not notice. Webjun 17, 2024 · spider bite faqs. What does a spider bite look like? A spider bite looks a lot like other bug bites, as well as some bacterial infections. It usually causes redness,. Webif the wound is untreated, it could lead to bruising, a blister, an open sore and scarring. What would cause a brown recluse spider to.