A young Hackney director braved thigh-high piles of bat poo, dead bats and cockroaches in caves five kilometres deep to film a BBC documentary about an endangered bat – without which there would be less tequila to drink.

Hackney Gazette: Director, Tom MustillDirector, Tom Mustill (Image: Archant)

Tom Mustill’s wildlife film The Bat Man of Mexico is narrated by David Attenborough for BBC2’s Natural World series, and tells the story of biologist Dr Rodrigo Medellin’s work to study and save the lesser long-nosed bat.

The bat crucially pollinates the agave cactus, from which tequila is made.

Filming for the crew of three entailed four months of sitting in the dark in snake and cockroach-ridden caves, crossing drug cartel country, getting caught in two of Mexico’s worst ever hurricanes, hornet attacks and losing tyres and vehicles on remote and storm-wrecked tracks as they followed the 1,500-mile migration journey of the species from Mayan jungle temples to the US border.

Mr Mustill, 30, who lives in Queensbridge Road, Haggerston said they were not prepared for the experience.

Hackney Gazette: Director, Tom MustillDirector, Tom Mustill (Image: Archant)

“The smell of the guano, or bat poo is pretty impressive, and you can’t be prepared for how hot and humid it is,” he said.

“You can be walking for an hour or so in the cave and it’s cold, there are indigenous people’s skulls from a thousand years ago lying around and pictures of their gods,

“It’s very eerie and lifeless, but then it starts to get warmer, and you hear the bats flitting around you, bugs are flying off the walls, it’s as if you’ve found a hidden world, it’s so full of life.”

He continued: “At first you recoil but very quickly you realise the bats know what they are doing and it becomes reassuring to have them flying around you, they are amazing, they never fly into you.”

The team walked, abseiled and crawled with cameras and kit through the caves, some of which had temperatures in the 40s, and humidity was so high lenses steamed up constantly.

Bat guano makes the air thick with ammonia and face masks are necessary to breathe, without which there is a high chance of contracting the potentially fatal lung disease, histoplasmosis.

Just 20 years ago the bats’ population was decimated, but through his work Dr Rodrigo Medellin has succeeded in bringing the mammal back from extinction and they will now be removed from the endangered species list.

Mr Mustill said: “I think people really underestimate bats and think they are creepy or gross but they are very clean and all the different species have different personalities, they are like very small dogs and very clever for their size, because they are social and live in groups, they are kind of watching each other and helping each other.”

One of the highlights for Mr Mustill was meeting his childhood hero Mr Attenborough, who agreed to narrate the film after Mr Mustill contacted him.

“It was magical working with him, he brings the script to life.

“He said one line so beautifully – ‘They found something very rare, and very weird’. He said it so perfectly, just like I’d had his voice in my head when I wrote the script.”

The documentary will be available to view on the BBC iPlayer for the next 12 days.