A study comparing swabs taken from chimp nests with those from human beds found that people's sheets and mattresses harboured far more bacteria from their bodies than the animals' beds did from theirs.
The researchers say their findings suggest that our attempts to create clean environments for ourselves may actually make our surroundings “less ideal”.
More than a third – 35 per cent - of the bacteria in human beds comes from our own saliva, skin and faecal particles.
Chimps’ beds may be cleaner because they make them freshly in treetops each day ZOOM DOSSO/AFP/Getty Images
By contrast, chimps - humans’ closest evolutionary relatives - appear to sleep with few such bacteria.
“We found almost none of those microbes in the chimpanzee nests, which was a little surprising," said Megan Thoemmes, lead author of the paper.
The researchers collected samples from 41 chimpanzee beds - or nests - in Tanzania and tested them for microbial biodiversity.
At 15 primates’ nests, researchers also used vacuums to find out whether there were arthropods, such as insects, spiders, mites and ticks.
"We also expected to see a significant number of arthropod parasites, but we didn't," said Ms Thoemmes.
In addition, the team were shocked to find very few fleas, lice and bed bugs – ectoparasites – in the chimp nests.
"There were only four ectoparasites found, across all the nests we looked at. And that's four individual specimens, not four different species,” said Ms Thoemmes, a PhD student at North Carolina State University.
She believes chimps’ beds are cleaner because they make them freshly in treetops each day.