The field of autonomous underwater robots is relatively young, but the curious-robots exploration method has already lead to some pretty interesting discoveries, says Hanumant Singh, an ocean physicist and engineer at Woods Hole Oceanographic Institution in Massachusetts. In 2015, he and a team of researchers went on an expedition to study creatures living on Hannibal Seamount, an undersea mountain chain off Panama’s coast. They sent a curious robot down to the seabed from their “manned submersible”—a modern version of the classic Jacques Cousteau yellow submarine—to take photos and videos and collect living organisms on several dives over the course of 21 days.

On the expedition’s final dive, the robot detected an anomaly on the seafloor, and sent back several low-resolution photos of what looked like red fuzz in a very low oxygen zone. “The robot’s operators thought what was in the image might be interesting, so they sent it over to the feature to take more photos,” says Singh. “Thanks to the curious robot, we were able to tell that these were crabs—a whole swarming herd of them.”

The team used submarines to scoop up several live crabs, which were later identified through DNA sequencing as Pleuroncodes planipes, commonly known as pelagic red crabs, a species native to Baja California. Singh says it was extremely unusual to find the crabs so far south of their normal range and in such a high abundance, gathered together like a swarm of insects. Because the crabs serve as an important food source for open-ocean predators in the eastern Pacific, the researchers hypothesize the crabs may be an undetected food source for predators at the Hannibal Seamount, too.

When autonomous robot technology first developed 15 years ago, Singh says he and other scientists were building robots and robotics software from scratch. Today a variety of programming interfaces—some of which are open-source—exist, making scientists’ jobs a little easier. Now they just have to build the robot itself, install some software, and fine-tune some algorithms to fit their research goals.

While curious robot software systems vary, Girdhar says some of the basics remain the same. All curious robots need to collect data, and they do this with their ability to understand different undersea scenes without supervision. This involves “teaching” robots to detect a given class of oceanic features, such as different types of fish, coral, or sediment. The robots must also be able to detect anomalies in context, following a path that balances their programmed mission with their own curiosity.

This detection method is different from traditional undersea robots, which are preprogrammed to follow just one exploration path and look for one feature or a set of features, ignoring anomalies or changing oceanic conditions. One example of a traditional robot is Jason, a human-controlled “ROV,” or remotely operated vehicle, used by scientists at Woods Hole to study the seafloor.