Craziest Cases of Animal Experimentation Throughout History

List Rules
Vote up the most shocking ways that animals have been experimented on

Animal experimentation, despite its substantial and well-earned controversy, has widely impacted modern medicine's understanding of physiology, genetics, and disease. In spite of these scientific gains, animal testing has also inspired some experiments many consider – even by the most conservative of estimates – to be unethical. Though scientists have developed alternatives to animal testing in recent history, doctors, researchers, and scientists alike have conducted plenty of ludicrous experiments on unsuspecting animals.

This list chronicles the most shocking and morally dubious of these animal-centric experiments. Although some – though certainly not all – of these incidents revealed what are now fundamental precepts of medicine, how these advances were made leave many, both in and out of the scientific community, conflicted. 


  • 1
    1,496 VOTES

    Cancer Researchers Made Frogs' Skin Transparent

    To help further their insight into organ growth and tumor development, in 2007, Japanese cancer researchers at Hiroshima University actually bred transparent frogs. These frogs boasted internal organs that were completely visible through their skin.

    Apparently, this innovation allows researchers to reduce the number of dissections they have to perform, since the frog's internal organs and blood vessels are all visible through their skin.

  • 2
    3,900 VOTES

    Injected Spiders Wove Spastic Webs

    In 1995, a group of NASA scientists studied the effects of various intoxicants on the web-weaving abilities of spiders. Ostensibly, they sought to determine the relative toxicity levels of the substances by examining the webs they created after injection. 

    What followed was most likely confirmation of anticipated results: the spider on weed wove a decent web, albeit incomplete; the spider on a stimulant wove quickly and poorly; the spider on a hallucinogenic wove a scattered, inefficient web; and the web of the spider on caffeine was off-center and asymmetrical.

  • 3
    1,739 VOTES

    Baby Jellyfish Were Ejected Into Space

    Baby Jellyfish Were Ejected Into Space
    Photo: Unknown / PxHere / CC0 Public Domain

    In 1991, Dr. Dorothy Spangenberg was studying the potential effects of zero-gravity on human fetuses. Since testing her research on actual fetuses would have assuredly crossed an ethical line, she and her team packed 2,478 baby jellyfish onto the Columbia space shuttle, ejected them into orbit, and watched for results. Initially, the jellyfish adapted well to the environment, and bred themselves up to a population of 60,000.

    Sadly, back on Earth, the new jellyfish were found to have greater “pulsing abnormalities” than usual – a syndrome commonly known as “vertigo.” The experiment demonstrated that, hypothetically, humans born in space might experience mobility issues once they land on Earth, similar to the phenomenon of "sea legs," often experienced by seafarers immediately after returning to land.

  • 4
    1,422 VOTES

    A Monkey's Head Was Transplanted To Another Body

    A Monkey's Head Was Transplanted To Another Body
    Photo: Charles J Sharp / Wikimedia Commons / CC BY-SA 4.0

    American researcher Robert White performed the world's first successful monkey-head transplant in the early 1970s. In a carefully-choreographed operation, White removed a monkey's head from its body and placed it on a headless specimen. Astonishingly, the monkey awoke and tried to bite one of the surgeons. The transplant recipient survived nine days before passing.

    In 2016, neurosurgeon Sergio Canavero successfully performed a monkey-head transplant. Canavero was already well-known at the time for attempting a human-head transplant in 2015.