Laughter is one of those universal things few of us can misinterpret – and we’re not the only animals to do it. Chimpanzees have a sense of humour and generally enjoy themselves. They also laugh. There is no doubt these two young chimps from Bossou Forest in Guinea ( below) are laughing: their body language is relaxed, there’s no tension around their faces and their mouths are open with the lower teeth exposed and upper teeth covered. Meanwhile, this female western lowland gorilla ( right) appears to be in ecstasy, relishing the rush of butterfly wings around her in a forest clearing.