Making big cats go wild wasn't the intention when Calvin Klein developed Obsession for Men 34 years ago, but that's one of the perfume's surprising side effects. Now, as the BBC reports, Banham Zoo in the UK is collecting old bottles of the fragrance as a treat for the lions, tigers, and leopards in its care.

Like many perfumes, the key ingredient in Calvin Klein's Obsession is animal musk. The musk used in Obsession is civetone, a pheromone secreted by small cat-like mammals called civets. When big cats like tigers and lions get a whiff of the scent, they go nuts for it and rub themselves all over the source. Experts suspect that cats interpret civetone as a kind of territorial marker and roll around in it as a way to mark the area with their own scent.

Zoos have long been aware of the cologne's popularity with big cats and have used it in their animal enrichment programs. At Banham Zoo in Norfolk, England, supplies are running low, and the zoo is asking anyone with an old bottle of Obsession at home to donate it. The cats respond positively to having a variety of scents spritzed in their enclosures, so the zoo will accept non-Calvin Klein fragrances as well.

Keeping animals in captivity happy isn't Obsession for Men's only alternate use. In 2018, wildlife officials in India shipped in bottles of the perfume with a plan to use it to lure a dangerous tiger out of the jungle.

[h/t BBC]