Although most black widow bites do not cause serious damage, their venom can cause symptoms such as nausea and muscle cramps. Bites are more dangerous for small children and elderly. The spiders are generally nonaggressive and only bite when they feel threatened. The best way to avoid a black widow bite is to keep skin covered when working outdoors especially with firewood and lumber, and use a pest repellant on clothing. Additionally, shake out clothing and shoes that are not often worn before getting dressed. If a bite does occur, clean the area with soap and water and seek medical help as soon as possible.