The emotional moment a group of chimpanzees saw daylight for the first time after being kept in a laboratory for their whole lives has been caught on film.
The video shows the animals edging out of the door hesitantly at first and looking curiously up at the sky.
But they then appear to celebrate their new found freedom by hugging each other and laughing.
The 38 chimps were taken from their mothers shortly after they were born and kept in a research facility in Austria.
They were used for tests based on diseases such as HIV and hepatitis and kept in isolation.
They were rescued in 1997 after the pharmaceutical company behind the research was sold and taken to a farm where keepers have since tried to reintroduce them to the outside world.
It is only now that experts felt the time was right and the chimps were ready to experience fresh air.