They've helped mankind get from A to B for millennia, but it seems horses understand us more than we think.
Scientists say the animals can recognise angry or happy human faces.
Reading human emotions is an extremely rare skill in the animal kingdom, with only dogs previously deemed able to tell the difference between a smile and a grimace.
But now a study has found horses are also intelligent enough to read basic human expressions.
Scientists from the University of Sussex showed 28 horses pictures of men they had never seen before, making both happy and angry faces.
When looking at the angry faces, the horses were more likely to turn their heads so they were using their left eyes - something they are known to do in response to negative stimuli.
Their heart rates also increased and they displayed more signs of stress than when they were shown happy faces, the journal Biology Letters reported.
Amy Smith, who co-led the study, said the horses' stronger reaction to negative expressions could be a mechanism that helps them respond to threats.
The scientists said the ability to read human faces could be an evolutionary trait, or something that individual horses learn over their lifetime.
- Daily Mail