Fly agaric mushrooms are poisonous. Ingestion of them is one of the most common causes of mushroom poisoning. Fly agaric contains muscarine, muscimol, and other toxic alkaloids, and its ingestion is soon followed by nausea, vomiting, diarrhea, excessive salivation, perspiration, watering of the eyes, slowed and difficult breathing, dilated pupils, confusion, and excitability. Illness usually begins within a few hours after eating the mushroom, and recovery usually occurs within 12 hours. Death is rare. Fly agaric is also a source of bufotenine, a weak hallucinogenic agent and poison.