Yuck.
Though I havent met the lemur...yet....Im sure that stapling the webbing on its paws to a board, then slowly pushing large darning needles up under the claws would be a start. That could perhaps be followed by the tried and true method of witch torture which involves dripping a cloth down the throat embedded with shards of glass and metal til it reaches the intestines...then yanking it out whilst singing loudly " Home on the range" would induce some profound spasms and shreiking until the blood fills the throat and larynx. An ingestion of battery acid would then be administered to internally "cauterise" the bleeding points, wherein one could if one chose to ......begin to administer small doses of strychnine to induce violent muscle spasms , but not too much or it would kill too quickly, and we dont want that. A soldering iron applied to the anus would reintroduce the shrieking and screaming again, with the added benefit of a pleasant sizzling noise and smell, though Im told that some find this a little nauseating.
Ah yeah, that was done on game of thrones...
Rat torture is a good one, wikipedia even has a short page on it.
I especially like the one from american psycho:
"In the 1991 novel American Psycho, the narrator Patrick Bateman performs rat torture on a kidnapped woman by cutting open her vagina enough to fit a plastic tube into and forcing a rat to crawl into her vagina. He removes the tube, staples her labia together, then watches as the rat eats the restrained woman from the inside out." - Wikipedia
I'm fairly certain our lemur is female... but if it's a male we can use it's rectum...
And who is to say we need to limit this to rats? maggots would also work well...
