Terrestrial animal Terrestrial animal The term terrestrial is typically applied for species that live primarily on the ground, in contrast to arboreal species, which live primarily in trees. There are other less common terms that apply to specific groups of terrestrial animals: Terrestrial invasion is one of the most important events in the history of life. Terrestrial lineages evolved in several animal phyla, among which vertebrates, arthropods, and mollusks are representatives of more successful groups of terrestrial animals. Terrestrial animals do not form a unified clade; rather, they share only the fact that they live on land. The transition from an aquatic
Non-reproductive sexual behavior in animals one of these two bonding. Homosexual parenting is very common, especially in birds. Homosexual pairs have better skills and larger nests than heterosexual pairs. Homosexual pairing can occur different ways, one example would be two female animals with offspring coming together and helping each other raise their offspring. Genital-genital rubbing, or GG rubbing, among non-human animals is sexual activity in which one animal rubs his or her genitals against the genitals of another animal. The term "GG rubbing" is frequently used by primatologists to describe this type of sexual intimacy among female bonobos, and is stated to be the "bonobo's