At any moment in time, one in every 20 male giraffes can be found amorously necking with another male. Or so says one study into giraffe homosexual behaviour. You probably wouldn't have learned about it in biology class, but homosexual behaviour is very common all across the animal kingdom (some zoologists estimate that about 1,500 animal species are known to display some form of it). In giraffes, that behaviour involves necking, caressing and mounting … and it’s more common than heterosexual interactions!