why cats always do the scrathes in every furniture?

I always heard they scrath their claws to sharpen them. I got my kitties a scratching post so they can sharpen there claws on it. Sometime when they walk across you there nails dig in I might buy some kitty finger nail clippers as I don't want to declaw them.

They need to sharpen their claws. Unfortunately, furniture seems to be very attractive to them. More attractive than scratching posts! I've had to keep my cat's claws clipped and put sticky tape on his favorite parts of the sofa to try and save it! Fortunately he likes the old crummy sofa with the cover better than the nice one!

mainly to help shed the old claws. i usually see outdoor cats using tree trunks for the same reason.9 times out of ten they'll stick to a scratching post indoors,but there's always one that'll aim for the furniture anyways.