Our boy Hogan does this exact same thing, and so we took him to the vet a when this behavior first began. He doesn't have adrenal disease, and the vet attributes this odd habit of his as just a behavioral problem. Hogan was used as a breeder before we brought him home, and so we thought his ear sucking was in some way related to his past history of having his way with the ladies. It also appears to be a behavior Hogan only exhibits when he's bored. An interesting twist to Hogan's dirty little secret is that he only sucks the ears of female albino ferrets -- he shares a cage with three to four sable girls, whose ears he leaves alone, but poor Snickers constantly suffers from his oral aural fixation (and before Annabelle died he sucked her ears too). Bitter apple didn't help -- he just made faces when he sucked on the white girls' bitter apple soaked ears -- and so we added a "girls only" hutch into their cage, which is reachable by a 3" diameter tube, through which Hogan refuses to pass. Leonard & Elayne http://cascade-ferret.org [Posted in FML issue 2979]