Videos of cats jumping back from aluminium foil are a popular internet trend. Owners use foil on tables to keep cats away. But experts say this only works for a short time. Cats find foil strange because it is smooth, reflective, and makes a loud crinkly noise. This noise can be irritating to cats' sharp ears. Dr Megan Conrad, a vet from Hello Ralphie, told The Dodo, “Cats have extremely acute hearing, and the strange crinkly noise that the foil makes when touched can be irritating to their ears.” Cats also dislike the feeling of foil with its smooth surface and rough edges. Dr Claudine Sievert of Stayyy said the texture unsettles cats. Some behaviorists add that foil may look like water to cats, which they avoid. The International Association of Animal Behavior Consultants says cats run away from threats instead of facing them. While foil can stop cats from jumping briefly, they soon get used to it. Many cats walk on foil without fear after a few tries. Some even play with it. Dr Conrad warns, “Some cats, once they overcome their initial uncertainty about this new shiny surface, will lose their fear of it and not find it threatening.” Dr Sievert suggests other methods like double-sided tape, which cats dislike because it feels sticky on their paws. Experts agree that blocking cats works best if combined with rewards and alternatives, like a special perch. Foil is just a short surprise, not a fix. Cats that want to climb will win in the end.