3D printing has entered the animal kingdom as biologists use the technology to observe animal behavior in otherwise hard to see locations. In the forests of Costa Rica, behavioral ecologists Daniel Mennill, and Stephanie Doucet, are observing the mating behaviors of yellow toads with the help of motorized amphibians called, “RoboToads.”

During the frenzied breeding season that lasts little more than one day, male toads change color from dull brown to lemon-yellow, explains Matt Warren in an article for Science. The transition to a yellow color helps the males identify females, which remain brown. The team wants to discover how females are able to choose among the similarly colored male toads. With the help of Lincoln Savi, Mennill and Doucet constructed and printed a 3D toad equipped with motors to make the models move around naturally. “3D printing is really advancing the questions that we’re able to ask as field biologists,” says Mennill.
Similarly, in Canada, biologist Grégory Bulté was able to study the mating habits of northern map turtles by printing 3D models of female turtles. By placing the turtles on the lakebed, along with cameras, the team was able to resolve whether males find larger, or smaller females more attractive. 3D printing is “almost an ideal system,” writes Warren—adding that multiple copies can be printed relatively cheaply. Not only is it allowing scientists to create models at finer scales, says Mark Hauber at the University of Illinois in Urbana, but using these new models also means people can easily replicate experiments.