A HEARTBREAKING video released by America's Humane Society has captured the moment when a troupe of lab chimps see the sky and feel the bare earth for the first time.

A warning before you watch the video. You're going to need a really big box of tissues. Seriously, grab the biggest box of Kleenex in the room and put it on your desk.



Actually, get a towel. Then watch the video.



If you're a little short on patience or time, forward to the moment when a chimp who's been a lab animal its whole life turns and looks at the sky for the very first time ever.



The confused yet awestruck look on its face is priceless.



Then there's the moment about 20 second later when a chimp pats another one on the back and rubs it in a movingly human gesture.



And they call them animals.

Perhaps the real animals are us, for keeping these beautiful, intelligent creatures in cages for much of their lives.



The chimps in the video were released from a US lab into Chimp Haven, a Louisiana facility set up to cater for what it hopes will be more and more of the liberated primates.



American scientists from the US National Institute of Health said in 2011 that they would phase out most invasive research on chimpanzees. There are currently around 1300 chimps in 11 different US labs.



The Institute produced an 86-page report describing how chimpanzees should be used for research only if there is no other way to study a threat to human health.



Previously, chimps have been used for a range of biomedical and other research. They are favoured by scientists because they share 99 per cent of our own DNA.



So basically, if you test stuff on a chimp, you can assume what happens to it will happen to people too.



Such tests will now only happen in extreme circumstances, and the world will hopefully see more scenes like the ones in this video which the Humane Society released.



To donate to Chimp Haven or sponsor one of their chimps, click here.

Need a shoulder to cry on? We're here @antsharwood and @newscomauHQ

Originally published as Lab chimps see sky for the first time