Some cats will roll around in catnip, rub their face in it, or chew on it. Others will simply smell it and then walk away. The effects usually last for about 10 minutes before wearing off. As it happens, this addictive quality is carefully engineered. Big Pet Food is a multi-billion-dollar industry which invests heavily in research into "palatants" – ingredients that make our pets want to eat their products. And from potently smelly chemicals usually found in rotting meat to an additive commonly added to potatoes to stop them discolouring, the quest to make the most scrumptious pet food has led to some surprising insights.

Big [pet food] companies have huge departments that make palatants," says Darren Logan, head of research at the Waltham Petcare Science Institute, part of the company Mars Petcare. "Just like we make them for humans, we make them for pets as well."The effect of catnip is through smell alone and not taste, so catnip is best provided in a form that cats can easily smell,’ explains Vanessa. ‘For example, toys filled with dried catnip or liquid catnip sprayed onto toys or a cloth. Today it's possible to buy specialised kibble for almost any kind of pet, from frogs to sugar gliders (a small marsupial). Most follow roughly the same formula – they usually contain some kind of base carbohydrate, assorted proteins and fats, sugars, a source of fibre, antioxidants or other preservatives, emulsifiers (which keep the fat in the food and prevent it from separating), vitamins and minerals, and colouring agents.

Pet food companies are now so successful at making food delicious that they're increasingly encountering a dilemma – it's almost too good. "The danger for cats and dogs today is the same as for people, it's overconsumption," says Andrew Knight, a professor of animal welfare and ethics at the University of Winchester.The morality side of things is up to you, but if you can ignore the guilt of laughing at your cat looking silly, you can rest easy knowing you’re not sentencing your feline pal to a life of drug addiction and petty crime. Many animals rely heavily on smell to navigate the world around them, and this is often the main sense that's targeted. While human noses contain around 50 million olfactory receptors, cats have 67 million, rabbits have 100 million and dogs have around 220 million. On the other hand, their sense of taste is generally less discriminating than ours – our relatively high density of taste receptors is thought to have evolved to help us cope with our diverse omnivorous diets. According to this really large-scale study that we've just finished, the animals on vegan pet foods seem to be just as happy as animals on meat ones," says Knight, who is hopeful about their future potential. Of course, as with anything, you should use catnip in moderation. If your cat eats too much of it, they may vomit or have diarrhea. But as long as you use it sparingly, your cat will be just fine.