Scientists often need to figure out ways of understanding processes they can’t see. Usually, that results in research much more mundane than that carried out by Dara Orbach, a researcher at Dalhousie University in Canada.

That’s because Orbach is aiming to understand reproduction in animals like dolphins, harbour porpoises and harbour seals. Rather inconveniently for her, these critters aren’t exactly exhibitionists: Much of their time is spent underwater and out at sea. So, she found a way to bring their mating habits to her, by studying their anatomy in the lab. A new paper published in the journal Proceedings of the Royal Society B recounts the latest results of her work.

Orbach was inspired by work done on insects and lizards. Researchers let them mate naturally, then dropped them in liquid nitrogen to flash freeze them and their active genitalia. It’s a technique she described to Newsweek as “really exciting, but totally not feasible for anything larger than a tiny insect.”