A new study reveals that when two male slipper snails stay together and make direct contact, they change into female sex, I4U reports.

According to the study published in The Biological Bulletin, the larger slipper snail changes into female faster than the smaller one.

"I was blown away by this result," said co-author Rachael Collin from Smithsonian Tropical Research Institute (STRI).

"I fully expected that snails would use waterborne cues to see their world."

The slipper snail enters the list of other animals such as Clownfish, wrasses, morey eels and gobies that were already known for switching their sexes.

Tropical slipper limpets, scientifically, called Crepidula cf.marginalis, live under the rock along the seashore and feed on plankton and other particles from the water.

Researchers suggest that the change of sex is advantageous to the slipper snails because large animals can produce more eggs as female. Researchers also believe that there must be some internal communication between the snails that helps determine the time and size to change sex.

"Slipper snails don't move around much, so you don't really think of them having complex reactions to each other," said Rachael Collins. "But this study shows that there is more going on there than we thought."

For the study, the researchers kept two males of different sizes in small cups and allowed them to be in contact with one another. The other snail pairs were prevented from touching one another through a mesh barrier. The larger snail pairs who made direct contact grew faster and changed into females sooner than those who were kept apart.