Some creepy creatures of the deep have creepier behavior that surprises even scientists.

The discoverers of three new species of sea spiders off the United States West Coast learned the creatures’ bizarre diet of methane-eating bacteria.

The findings were published in the Proceedings of the National Academy of Sciences on 16 June, CNN reported.

Unlike their other relatives that use tubelike fangs to suck the juice of their prey, the sea spiders of the Sericosura genus lack such appendages and instead let microbes inside methane bubbles to stick in their exoskeletons to be able to steadily eat the gas, according to CNN.

In turn, the spiders eat the microbes, an example of a symbiotic relationship in the dark depths of the ocean.

Meanwhile, Chinese scientists published their findings on prehistoric fungus in the 11 June issue of the journal Proceedings of the Royal Society B: Biological Sciences.

Yuhui Zhuang, a doctoral student at the Institute of Paleontology at Yunnan University in southwestern China, observed the Paleoophiocordyceps gerontoformicae and the Paleoophiocordyceps ironomyiae preserved in a glob of 99 million-year-old amber sourced from Myanmar, using optical microscopes.

The first was growing from the brain of an ant that was also in the amber, while the second was coming out of the head of a fly, likewise preserved in the fossil resin.

The rare “predators” of insects in the Cretaceous period, after infecting their prey, controlled the host to propagate, eventually killing the zombies later.

João Araújo, mycology curator and assistant professor at the Danish Natural History Museum, said the species of fungus that infected the prehistoric ant may be an ancestor of zombie-ant fungi, and thus likely controlled its host’s body in similar ways, according to CNN.