snuff.

PLEASE TAKE YOUR CAT TO THE VET IF YOU SEE THEM DOING THIS BEHAVIOR OVER TIME.

It’s called “head pressing” and it occurs in dogs and cats. 

Head pressing is characterized by the compulsive act of pressing the head against a wall or other object for no apparent reason. This generally indicates damage to the nervous system, which may result from a number of varying causes, including prosencephalon disease (in which the forebrain and thalamusparts of the brain are damaged), or toxic poisoning.

http://www.petmd.com/cat/conditions/neurological/c_ct_headpressing

http://www.vet.cornell.edu/FHC/health_resources/toxoplasmosis.cfm (head pressing is listed as a symptom)

Sea otters have oil glands in their cheeks, and the vigorous rubbing is how they extract the oil, which then forms a layer on top of their fur.