Animals may live in groups or they may be solitary. Sooner or later, however, all animals must make contact with others to reproduce. In each animal species, social behaviors have evolved that optimize individual fitness. Some patterns of...

  Numerous techniques have evolved to optimize feeding. The goal is to maximize the amount of food eaten while minimizing the energy expended to obtain it and minimizing the risks of being injured or eaten. Some foraging behaviors follow: 1. Herds,...

  There are four stages in the growth and development of animals. The first is gametogenesis, the formation of sperm and eggs. The second includes embryonic development, which begins with fertilization of the egg and continues to birth. The third...

  Communication in animals is commonly used in species recognition, in mating behavior, and in organizing social behavior. Communication occurs through the following mechanisms: 1. Chemical. Chemicals used for communication are called pheromones....

  The human female reproductive cycle is characterized by events in the ovary (ovarian cycle) and the uterus (menstrual cycle). The purpose of these cycles is to produce an egg and prepare the uterus for the implantation of the egg, should it become...

  Three kinds of movements are commonly found among animals: 1. Kinesis (plural, kineses) is an undirected (without direction) change in speed of an animal’s movement in response to a stimulus. The animal slows down in a favorable environment...