Seven snorkeling grandmothers discovered almost 250 deadly sea snakes.

Bizarre on Female First

Bizarre on Female First

The New Caledonia women - who are in their 60s and 70s - decided to take regular excursions to explore a snorkeling spot where 30 of the potentially lethal serpents had been spotted over three years, and the group found 249 of the animals.

Claire Goiran - from the University of New Caledonia - said: ''As soon as the grandmothers set to work, we realized that we had massively underestimated the abundance of greater sea snakes in the bay.''

Rick Shine of Macquarie University added to CNN: ''The incredible energy of the grandmothers and their intimate familiarity with 'my' study area have transformed our understanding of the abundance and ecology of marine snakes in this system.''