Bear Grylls

High points on low plains, and low points on high peaks...

In the programme in the French Alps, you spent a night in a snow cave that you'd dug into a mountain. You described it as the worst night of your life. Was that true?

It would certainly rank quite high. When I've been on climbing expeditions you've always got sleeping bags, a roll mat and food. When you've got nothing, it's really hard. Similarly, I'd spent time in the jungle before, with the army, but I'd never done it with no mosquito nets, no hammock, no waterproof, no macheté.

They're all little factors, but they become major hurdles when you're getting bitten alive all night. You've got snakes and scorpions crawling over your legs in the night; you're struggling to get a fire going; and struggling to get any food or drinkable water. It's significantly harder, and I've really struggled through a lot of these things.

I think one of the nice things about the series is that it's very human, it's very real, and it's not always perfect. It's not 'this is how you build a canoe or make a fire' it's 'I've got to make a fire or things will be dire here'.

What was your best moment in making the series?

I think one of the biggest privileges for me was in Kenya, where I came across a lion kill at about 5am. A zebra had stumbled across a pride of lions in the night and the lions had just taken it down and then drunk the blood and eaten the soft organs. They'd eaten so much meat that they'd had to go off and find water, leaving the zebra to the vultures.

I'd been walking through the night and when I found the kill all the vultures scattered – they were so full of meat that they couldn't take off, so they were waddling away. But the carcass of the zebra still had a third of the meat on it. I was able to eat the meat raw straight off its neck.

It was somehow a real privilege to be there eating the same thing as the kings of the animal world, seeing how they operated at the sharp end, living as early man had done.

And the worst moment?

I had to do a quite scary swim across an alligator-infested river in the swamps of the Everglades. There were some extremely big alligators on the banks. They can stay submerged for about 45 minutes, so I watched for 45 minutes to make sure there were none still lurking on the bottom and they were all on the banks.

The way you need to do it is to swim underwater, because a lot of alligator attacks are cases of mistaken identity, where they think your bobbing head is a bird or something. So I had to swim this 50 metre-wide river underwater in this murky stuff. I couldn't see much, and that was pretty scary.

And I had a shark incident on a raft in the South Pacific. But I think in many ways the worst moments are those times when you're in the middle of the rainforest and it's been torrential rain for 48 hours and you've got no waterproof and no food, there's no drinkable water, you're lost, everything you have is soaking, and you think 'What the hell am I doing here?' But I always carry a little laminated picture of my wife and kids that I have stuffed into the insole of my shoe, and that's my 'hope packet'.