The fruits have evolved to be eaten by animals, which eat the flesh surrounding the hard endocarp or ingest the entire fruit and later vent the endocarp. If the endocarp is crushed or damaged during ingestion or digestion, the animal will be exposed to the toxins within the seed. The processes of mastication and digestion, and the degree of immunity to the particular toxins, vary widely between species, and there is accordingly great variation in clinical symptoms following ingestion. The fruits are poisonous or narcotic to humans if eaten in large quantities. According to Chinese medical literature, human poisoning can occur if 6–9 fruits, 30–40 seeds, or 400 grams of bark are eaten. The toxins include neurotoxins and unidentified resins, found mainly in the fruits. The first symptoms of poisoning appear a few hours after ingestion. They may include loss of appetite, vomiting, constipation or diarrhea, bloody faeces, stomach pain, pulmonary congestion, cardiac arrest, rigidity, lack of coordination and general weakness. Death may take place after about 24 hours. As in its relatives, tetranortriterpenoids constitute an important toxic principle. These are chemically related to azadirachtin, the primary insecticidal compound in the commercially important neem oil. These compounds are probably related to the wood and seed's resistance to pest infestation, and maybe to the unattractiveness of the flowers to animals. The plant is toxic to cats. However, these toxins are not harmful to many species of bird, who gorge themselves on the fruit, eventually reaching a "drunken" state. The birds that are able to eat the fruit spread the intact seeds in their droppings.