An animal defending against a predator may engage in either "fight or flight" or "tend and befriend" in response to predator attack or threat of attack, depending on its estimate of the predator's strength relative to its own. Alternative defenses include a range of antipredator adaptations, including alarm signals. An example of an alarm signal is nerol, a chemical which is found in the mandibular glands of "Trigona fulviventris" individuals. Release of nerol by T. fulviventris individuals in the nest has been shown to decrease the number of individuals leaving the nest by fifty percent, as well as increasing aggressive behaviors like biting. Alarm signals like nerol can also act as attraction signals; in T. fulviventris, individuals that have been captured by a predator may release nerol to attract nestmates, who will proceed to attack or bite the predator.