Cats are natural climbers. Their strong backs and hindquarters give them tremendous jumping power, according to the American Society for Prevention of Cruelty to Animals (ASPCA). Cats often climb in places where they are unwanted or it's unsafe, such as windowsills where plants are located. Fortunately, there are means available to discourage cats from climbing where they don't belong.
Apply double-sided tape to the area. The cat will experience the unpleasant sensation of sticky paws, which will discourage her from climbing onto the window sill. The tape won't cause permanent damage. Baking trays or aluminium foil also provide unpleasant stimuli for cats and can be substituted for double-sided tape.
Supply an alternative resting place. Cats climb window sills because looking out the window is a form of amusement for them. They also like sitting in the sun. Providing an alternative which supplies these features can discourage cats from climbing onto a window sill.
Use a commercial repellent. These devices startle the cat when she jumps onto the countertop by releasing an object or a blast of compressed air. The cat associates climbing onto the window sill with an unpleasant experience, which can discourage future climbing.
Cat's climb for food. She may be climbing in search of food if she's hungry. Try putting citrus or mint plans on the window sill. Cats don't like plants with a citrus or minty smell. Rosemary also repels cats.
Avoid spraying your cat with water or yelling at her when she climbs onto a window sill. This will only condition your cat to be afraid of you.