Understanding Cat Scratching Behaviors

Help! My cat is ruining my furniture!

Help! My cat is ruining my furniture!
Anyone who has a cat, and even those that don’t, know that cats like to scratch. If furniture could talk, your couch would tell you that cat claws are worse than a thousand samurai swords. Cat owners love their house tigers and even though furniture is replaceable and some scratch marks can be hidden, wouldn't it be nice to prevent this from happening?