Researchers have identified several new species of chirping pill-millipedes in Madagascar. Unfortunately, a number of these newfound species are already in danger, with their ecosystems shrinking to a smaller size every day.

According to a study published in the journal ZooKeys, all of the species discovered belong to the genus Sphaeromimus - Latin for "small ball animal."

Most pill bugs are just that - small. However, some of these newly discovered pill-millepedes can actually get up the size of a ping pong ball.

Madagascar is not known for its small insects. According to the study, these newly discovered millipedes actually share habitats with the region's well known giant pill-millipedes, which often approach the size of a baseball even when curled into a ball due to a genetic tendency for gigantism.

Despite similar size and habitat, the newly discovered bugs were found to be completely unrelated to their large neighbors, instead exhibiting genetic similarities to small pill-millipedes found in India.

"This relationship dates back more than 80 million years to at least as early as the Cretaceous period, when dinosaurs walked the Earth and India and Madagascar were connected," according to a press release accompanying the study.

Study author Thomas Wesener has been studying various Sphaerotherium species for years, fascinated with the fact that although they don't have a means to hear themselves, male versions of the millipede actually chirp.

"Females probably recognize the vibrations of the male," Wesener told Wired back in 2011. He explained that the fine hairs on a female millipede's legs likely allow it to detect the chirps of a male trying to coax it out of a defensive coil so that they can mate.

Unfortunately, Wesener's latest discoveries were often found in microendemics - tiny fragments of unique habitat. One species, the S. saintelucei, is likely the most endangered millipede in all of Madagascar, as it is found in a habitat so small that no large vertebrate species can survive in it.

The study was published in ZooKeys on June 6.