What is the biggest thing a whale can swallow

• Animals
• Explainer

Despite occasional reports of whales scooping people into their mouths, it’s incredibly rare—and for all but one species, swallowing a human is physically impossible.

On Friday, a lobster diver made headlines when he described miraculously surviving being “swallowed” by a humpback whale off Cape Cod, Massachusetts. Michael Packard told the Cape Cod Times that he felt a shove, and “the next thing I knew it was completely black.” He recalled struggling inside the whale’s mouth for about 30 seconds before it surfaced and spat him out.

Though a humpback could easily fit a human inside its huge mouth—which can reach around 10 feet—it’s scientifically impossible for the whale to swallow a human once inside, according to Nicola Hodgins of the Whale and Dolphin Conservation, a U.K. nonprofit.

A humpback’s throat is roughly the size of a human fist, and can only stretch to about 15 inches in diameter to accommodate a bigger meal. 

In Packard’s case, she says, he was likely “engulfed as opposed to swallowed” before the whale realized its mistake and immediately spat him out—likely a traumatic experience for both Packard and the whale, which was just trying to eat some fish.

“[Packard] was in the wrong place at the wrong time,” Hodgins says.

It’s not the first time that humans have purportedly ended up in a whale’s mouth: In 2020, kayakers were caught in the mouth of a feeding humpback in California, as was a tour operator in South Africa’s Port Elizabeth Harbour in 2019. Most famously, the Bible tells the story of Jonah, who was swallowed by a whale to save him from drowning. Even Pinocchio’s father Geppetto is swallowed by a whale in the classic children’s story.

The idea of whales swallowing humans has long been a part of mythology—so much so that many people believe it to be true. Yet it’s scientifically impossible for all but one whale species—the sperm whale—to swallow something as large as a person.

What whales actually like to eat

On the rare occasion that a human finds themself inside a whale’s mouth, it’s almost certainly an accident—in part because humans are not what whales eat.

Toothed whales, such as sperm whales, have teeth and feed on prey including squid and fish. Meanwhile, baleen whales—such as humpback, blue, gray, and minke whales—have special bristles in their mouths instead of teeth and eat tiny prey such as plankton, krill, and small fish.

Known as baleen, these bristles are made of a strong yet flexible protein called keratin—the same thing human hair and nails are made of—and are arranged in plates like a comb. When feeding, the whale takes a huge gulp of seawater and uses the baleen like a sieve to retain food in its mouth while pushing the water out through the gaps.

Of the 90 known whale species on Earth, sperm whales are the only species with throats large enough to technically swallow a human. The 65-foot-long mammals have large esophaguses to feed on larger prey such as giant squid, which they sometimes swallow whole. In fact, colossal squid—which can reach 46 feet long—have been found inside a sperm whale’s stomach.

While it’s physically possible, it’s “a billion to one thing” for a sperm whale to swallow a human, in part because encounters are so rare.

Most people are “never going to get a chance to see a sperm whale in [their] lifetime,”  says Rob Deaville of the Zoological Society of London’s Cetacean Strandings Investigation Programme. While sperm whales are widely distributed around the world, these deep-diving animals live mostly in the open ocean, and regularly spend time at depths of over 10,000 feet.

Threats to whales

So there’s no need to panic next time you’re swimming in the ocean, especially because whales are not aggressive toward humans. Instead, Deaville says, it’s whales that should be more fearful of us because of the “wide variety of man-made pressures and threats out there.”

Humans can harm whales through hunting, pollution, habitat destruction, entanglement in fishing nets, ship strikes, and more. Irresponsible tourist behaviors—such as getting too close—can also be distressing for whales.

If you ever see one of these gentle giants, experts recommend following responsible wildlife watching guidelines—including giving the animals plenty of space, observing from a distance (with binoculars if possible), and avoiding any actions that scare, startle or panic them.

 As for Packard, he told the Cape Cod Times that he planned to get back to diving as soon as he healed from his injuries, which included soft tissue damage but no broken bones.