The use of monkeys in animal research in the U.K. is declining rapidly, according to the BBC. Government statistics cited in the story show that procedures for this class of research animals dropped 47% in 2011, meaning fewer monkeys were used for everything from scans to blood samples or the testing of vaccines and cancer drugs. Tests involving rats and guinea pigs are also on the decline, but tests involving fish rose 15%, according to the story. And trials involving mice are also increasing. Officials said they were not sure why scientific testing procedures involving primates declined, but noted that more mice and fish are being bred for clinical trials, which helped lead to a 2% overall increase in the number of animal experiments. Story