With their large and dark eyes and intelligent dog-like faces, seals are considered adorable ocean creatures. Recent incidents, however, reveal a deadlier side of these lovable animals.

Disturbing behavior among seals is being confirmed and experts warn seals will one day attack human swimmers. Previous reports about unnatural seal behavior involved their rape of penguins.

Like Us on Facebook

A recent investigation found grey seals are to blame for the majority of attacks that left hundreds of stranded harbor porpoises mutilated and washed-up along the shores of The Netherlands, United Kingdom, Belgium and France.

Experts were surprised because grey seals mostly prey on fish. After the investigation, they concluded grey seals might challenge much larger animals, possibly even humans.

"Grey seals use their 'hands' to hold large prey and their teeth to tear off bits and pieces, so they do not have to swallow large prey whole. This is why they can also take on large prey," said lead author Mardik Leopold of the Wageningen University and Research Center.

Researchers from Institute for Marine Resources and Ecosystem Studies in Holland assessed the remains of over 1,000 mutilated porpoises that washed-up on the North Sea shorelines over the past 10 years. The cause of the mutilations has been a mystery to researchers.

Their theory was that porpoises were caught in boat propellers or maimed by scavengers after being caught in fishing nets.

Recently, however, scientists confirmed grey seals were the culprits using DNA evidence. They analyzed the fresh wounds on porpoises and found out the majority had bite and claw marks consistent with grey seal attacks. Some of the porpoises also tested positive for grey seal DNA and that proved seals were the attackers.

Nearly 180,000 grey seals live along the Scottish coastline and surrounding area of the British Isles. They're 11 feet long and weigh over 660 lbs., making them the largest carnivorous animals in Britain.

Experts warn residents and tourists to stay away from the seals because of the possibility they'll attack humans. They also suggest there should be warning signs around recreational water areas.

Tagsgrey seals, grey seals murdered harbor porpoises, harbor porpoises, animal kingdom, predators, ocean predators, Seals, Grey Seals Deadliest Predators