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.
When a cat holds its tail low to the ground and the tail is puffed, the cat is expressing fear or uncertainty. A twitching tail, especially when the cat is sitting, expresses annoyance, while a cat that lashes its tail back and forth is angry. The faster the cat lashes its tail, the angrier it is. Most cats do not want direct conflict and use these very visible cues before the conflict escalates into bites and scratches.