The Xenocytes are like alien leeches that attach to a human host, which create what they are commonly known as the DNAliens. As they attach to their host, they take over the personalities of the people they possess and control them. Within hours, the Xenocytes will completely cover the host's bodies turning into even more DNAliens. Xenocytes eggs were created from an egg-laying machine. The eggs are hatched underwater in large artificial rivers (that look similar to the pools used to store radioactive material) . After hatching the Xenocytes are stored in boxes filled with DNAlien slime, probably to keep them fresh, considering that in the end of "Max Out" they were seen living in open air and many were shoved into wooden crates with seemingly no DNAlien slime it suggests that Xenocytes are amphibious lifeforms. Kenneth Tennyson, Gwen's older brother, was near to becoming a DNAlien from this cause in "Max Out". Towards the beginning of the episode, a Xenocyte was close to attaching itself to Max Tennyson, until he crushed it. The Xenocyte eggs were going to ship out althroughout the country, but the Tennysons and Kevin Levin managed to stop that from happening. Towards the end of the episode, DNAliens, disguised as humans, were shown collecting the remains of the Xenocytes from the Highbreed base and throwing them in trash cans.