Ours both did when they were younger -- up until age 13 or so. Now, at age 15, neither gets too excited, but every once in a whole, I'll hear a funny noise and investigate and discover one or the other has dragged out some catnip toys. When they were spry, they'd go nuts. We had cat mats with cat nip in the filling and they loved them! We put them in their carriers for the plane to the UK -- not with fresh nip, but they were covered in drool and fur and we figured that it helped make the kennel a little more familiar!