When it comes to homosexuality, humans aren’t the only gay ones. Studies have proven several other species ranging from killer whales to penguins, have high rates of same-sex activity.

Giraffes have one of the highest percentages of same-sex activity at 94%. Ironically, males commonly show their anger towards other members of the same sex through a process called necking. Necking, as seen on Good Morning America, is when giraffes hurl their necks into the side of their opponent’s neck. In an article on Gay Star News, Joe Morgan says necking can lead to sexual arousal. Even when females are present, males often times chose to neck with other males.

Similar to giraffes, bottlenose dolphins also find great satisfaction with being with the same sex. According to Listverse, one same-sex relationship lasted for seventeen years. Additionally, researchers discovered a whole pod of dolphins, all male, content with interacting with only the same sex.

Perhaps this deep attraction to the opposite in several species is due to epi-marks. Epi-marks. Epigenetics regulate gene expression in cells. An article posted on Time Magazine explains the theory as this:

“Normally, these epi-marks are erased after they are activated, but if those marks are passed down to the next generation, the same epi-marks that protected a man in utero may cause oversensitivity to testosterone among his daughters, and the epi-marks that protected a woman in utero may lead to undersensitivity to testosterone among her sons. (Blue)”

The change in testosterone may then lead to heightened attraction to the same sex, as seen in the case of the giraffes and dolphins.

While the biology behind homosexuality is still largely controversial, many scientists have sought to explore more experiments based on the theory of epigenetics. Cutting-edge ideas mixed with traditional methods continue to broaden scientists understanding of the human brain, and possibly one day, will solve the mystery that is attraction.