Marijuana, the most often used illegal drug in this country, is a product of the hemp plant, Cannabis sativa. The main active chemical in marijuana, also present in other forms of cannabis, is THC (delta-9-tetrahydrocannabinol). Of the roughly 400 chemicals found in the cannabis plant, THC affects the brain the most.
Cats 'vibrate' when marking territory-spayed cats can also 'dry' spray. Spayed male cats urine doesn't smell. They swish their tales as a sign of annoyance or anger. If the tip of the tail 'trembles', it's quite often a sign of being 'unsure' about something. Source(s): Cat owner.
Cat Ear Mites. Cat ear mites are another parasite that often affects cats. These parasites are crab-like in appearance and attack the ear and ear canal of felines. Cat ear mites are extremely irritating to cats. They cause scratching and head shaking as cats try to relieve themselves from these biting parasites.