In Canada, bear mischief has been on the rise for the past few weeks. The Globe and Mail spoke with bear-attack expert Stephern Herrero about it and within his Q&A one thing in particular stuck out: if you play dead during a bear attack, you’re pretty certain to be dead by the end of it. Here’s what he said:

The most tragic one is people playing dead during a predacious attack. Because in that circumstance, the bear just keeps on chewing.

This might surprise you, because a lot of places include “playing dead” as part of their bear attack advice. PBS says you should. ”If the animal makes contact, curl up into a ball on your side, or lie flat on your stomach,” they write. “Try not to panic; remain as quiet as possible until the attack ends.” Mountain Nature says “playing dead in a daytime grizzly encounter tends to reduce the level of injury sustained by most attack victims.” Another advice site says that “even if the bear bites you continue to play dead. Once he realizes that you are not a threat he may leave.”

This is an old idea. In 1806, an explorer wrote of a Native American woman who, when attacked by a bear, dropped to the ground and was still. The bear ran off to attack her husband. Another California pioneer wrote “if the man lies still, with his face down, the bear will usually content himself with biting… for a while about the arms and legs, and will then go off a few steps and watch… the bear will believe him dead, and will soon… go away. But let the man move, and the bear is upon him again; let him fight, and he will be in imminent danger of being torn to pieces.”

But what does the science say about this? Well, the key to understanding Herrero’s advice there is understanding the word “predacious.” Predacious attacks are those in which the bear is actually hunting you, rather than responding defensively. A mother bear defending her cubs is not hunting you, she’s just trying to make you go away.

So if the bear attacking you is in defense mode, playing dead is probably the right thing to do. One study on bear attacks writes that “the bear may swat at or bite the victim, but the if victim can retain the presence of mind to lay still, it is likely that he or she will survive the attack.” A look at the bear attacks in Yellowstone National Park between 1931 and 1984 found that 80 percent of the hikers that fought back against the bears were injured. Hererro’s own book suggests playing dead during “sudden encounters,” when you and the bear surprise one another and the bear attacks in defense.

But what if the bear is attacking you for real? What should you do then? Pretty much all scientific advice guides agree that if the bear sees you as food, you should fight. “The victim should always fight back in the event of a clear predatory attack, such as being pulled out of a tent, regardless of species,” one study says. Another strategy that Herrero’s book says might work is dropping something as a diversion, like a camera, to distract the bear while you escape.

While we’re on the topic of bears, it turns out that some of the other bear survival tips are also misguided. Many places say to climb a tree, which is often a bad idea since many bears can probably climb that tree faster than you can. Don’t run away either, since bears can run through a forest far faster than you can too. The Yellowstone study says that of all the hikers attacked, 61 percent hikers who were injured tried to run away or climb trees.

In the end, your odds against a 1,500-pound brown bear aren’t great. They’re bigger, stronger and faster than you, and have likely killed far more living beings than you have. The key to not being chewed on alive, slashed to death, or otherwise mauled is to know what kind of situation you’re in and respond calmly and appropriately. A tough task when you’re under attack by a bear.

More from Smithsonian.com:

How To Avoid Being Eaten By A Black Bear

What Should Be Done With Yachak, the Cattle-Killing Bear of the Andes