Brown Recluse Spider, Extremely Dangerous, contains 9 poisons, similar to rattlesnake venom. Self Treatment - Stage 1 - If you've been bitten by this spider (or any spider), the 1st thing you should do is apply activated charcoal directly to wound (keep in medicine cabinet for poison emergencies). You can find it in capsules sold at health food stores, or you can buy it in the aquarium dept. of a grocery store. Charcoal must be finely ground before it's used. Apply thick paste to bite area.