More than 2600 monkeys in Britain have experienced torture in the name of scientific experiments and have been put through gory experiences like having their skulls opened up while still alive.
According to the British Union for the Abolition of Vivisection (BUAV), scientists at a university in Edinburgh last year force-fed pregnant marmosets with toxic chemicals used in plastics to monitor the effect on the sexual organs of their unborn babies.
At another university, two anaesthetised monkeys had their skulls sawn open and electrodes were inserted into their brains.
Their eyes were then kept open and focused on a TV screen for five days to test whether the "after image" is in the eye or the brain, the Daily Express reported Sunday.
Most experiments were done in the name of medical science, but animal rights activists claim many of the reasons were "completely frivolous".