animal sexual behavior takes many different forms, even within the same species and the motivations for and implications of their behaviors have yet to be fully understood. bagemihl's research shows that homosexual behavior, not necessarily sexual activity, has been documented in about 500 species as of 1999, ranging from primates to gut worms. homosexuality in animals is controversial with some social conservatives because it asserts the naturalness of homosexuality in humans, while others counter that it has no implications and is nonsensical to equate animal behavior to morality. on the other hand, social liberals and many gay people believe homosexuality is natural, and therefore find the existence of homosexual sex in animals unsurprising. animal preference and motivation is always inferred from behavior. thus homosexual behavior has been given a number of terms over the years. modern research applies the term "homosexuality" to all sexual behavior (copulation, genital stimulation, mating games and sexual display behavior) between animals of the same sex.