There we have actually very specific reasons why your dog do weird things like sniff butts or scoot their butts across the carpet.

Eating Grass

You’ll realized that there are some Dachshunds that love to eat grass every now and again even though it makes them throw up. In spite that looks unhealthy, Dachshunds usually do this to get a better digestion, treat intestinal worms, or fulfill a nutritional need like a lack of fiber.
Post-Bath Hyperactivity
Your Dachshund after taking a bath can get a bit hyper after it. Dachshunds are so happy to be out of the water, belive it or not. They may shake, rub, and run around just to get dry and rid of the sensation of being wet.