Stress is a factor not only in the best human families; it also appears among animals. Scientists gave parent and offspring birds a hormone pellet to increase their “stress levels”, with the result that stressed offspring not only intensified their begging but also received more food than “relaxed” chicks. Nevertheless, increased begging was not the determining factor of the parent-offspring interaction. When parent birds were stressed, they automatically reduced offspring feeding and spent more time searching for food for themselves.