Tadpoles, virtually indestructible microscopic animals that can withstand radiation and extreme temperatures, lead a very active or even wild sex life, as evidenced by video recordings of scientist James Weiss, reports Business Insider.

James Weiss, a videographer known for the YouTube channel Journey to the Microcosmos and the book The Hidden Beauty of the Microscopic World, is an expert in using microscopes to study microbes in ponds, lakes, rivers and seas.

Studying these microscopic creatures for weeks, he captured images of tardigrades mating for up to two hours at a time.

He also recorded three tadpoles having sex for 30 minutes, one of the first known records of group sex in these microscopic creatures, also called water bears.

Researchers first published details of tardigrade mating behavior in a 2016 paper, but other observations about their sex remain fairly limited.

“Until recently, not many people have studied tardigrades, so these observations all come from a few well-known tardigradologists,” Weiss said. (Yes, “tardigradologist” is a real word, he added.)

“I don’t study tardigrades in a traditional institutional way, but because I’ve been interested in them for a long time, I’ve collected a lot of data and noticed some unique behaviors,” Weiss said.

One of those unique behaviors? A sexual match between three slow-moving animals.

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