Yes, roosters do exhibit homosexual behavior.
Worms are hermaphroditic, so no, they do not exhibit homosexual behavior or heterosexual behavior.
Animal sexuality is quite different than human sexuality. There are many examples of homosexual and bisexual behavior patterns in the animal kingdom.
Chimpanzees
Neon gobies exhibit symbiotic behavior is known to be jumpy. The behavior can go from one thing to another.
Some monkeys have demonstrated gay or bisexual behavior, but not all of them.
Although there is no documented evidence that zebras exhibit homosexual behavior, there is a widely-held view that most mammals, possibly all mammals, have specimens exhibit homosexual behavior at one time or another.
Natural behavior
Yes, they do.
innate behavior
Helmut Albrecht has written: 'Chimpanzees in Western Africa' -- subject(s): Behavior, Chimpanzees, Primates
Yes, rams (male sheep) can exhibit homosexual behaviour.