Most people have fond memories of going to the zoo. The experience of waiting, in anticipation, to see a lion or a tiger come out of its cave. Leaning close to the glass as a chimpanzee or orangutan comes closer.

However, the animals we witnessed on those visits didn’t feel the same thrill that we did. They were, quite possibly, in great pain. We’ve come to accept that other sentient beings can be used for entertainment or pleasure, but it may be time reevaluate that belief. It turns out that zoos have a dramatically negative effect on the animals they’re supposed to protect. And although zoo advocates would argue that endangered species are protected by zoos, the overwhelming consensus is that it’s just not true.