We've a small fodder crisis with the sheep. They are separated into two flockettes: one of mothers-and-lambs (all doing well enough, thanks) and the other of 'empties'. The former are privileged over the latter and we are waiting a few weeks to get a cut of hay off the 4 big meadows before turning everyone out to graze the aftermath. Accordingly, empties are on short commons and for the last few days, I've let them (N=5) out, under strict supervision, into the yard in front of the house where there is loads of grass which I'd have to mow aNNyway. Strict supervision is necessary because there are a handful of roses (mmm, good) and other shrubs around the edge of the yard. It's working well, they gallumph out and start scarfing up the grass (because they are all hank); I read a book or fill buckets of water or fetch in some firewood and give them the hairy eyeball if they start in on the roses. After an hour they are full up and more or less willing to be turned out of the yard again.
Turns out that one of the sheds has a pair of glass doors and a few times one or other of the sheep has looked up from hoovering grass to see a strange ewe gazing back at them with grass spilling out of her chops. I would interpret the reaction as being mild curiosity, what they see (but don't smell) is more interesting than more grass but only for a few seconds and maybe a second look. Not much data there but I was reminded of these ovine stares when I found this io9 report about jungle animals and their reaction to a mirror in their territory. At the moment, the list of animals which have 'self-awareness' is rather short. Self-awareness is what remains when you overcome the shock of the new and turn a mirror into a tool to see the back of your head or realise that the image and yourself are both scratching their arm-pits at the same time. Chimps, dolphins and elephants are demonstrably able to make this cognitive transition and this makes an unsurprising trinity in the folklore of 'animal intelligence'. But pigeons have been shown to be as good at recognising themselves as a 3 year old child! Whereas gorillas, our nearest rellies after chimps, don't seem to get it and nor do cats and dogs. It takes a lot of patient training to accumulate the scientific evidence that animals are actually doing what we attribute to them with 20/20 anthropomorphism. I reckon that the list self-aware species will get longer as people devote the time to carefully controlled observation.
I don't think there is any evidence that sheep follow the advice of Solon [and a dozen other ancient sages] to γνῶθι σεαυτόν know themselves. But they certainly know each other, even at a significant lapse of time. In 2001, the scientific world was surprised and delighted to learn that face-recognition had been applied to sheep and that they could recognise their pals even after several years separated. Humans and sheep have been shown, by MRI scans, to fire up certain particular regions of the brain when processing faces. I haven't seen whether they are the same regions in both species - must find out! What awes me about psychologists is how they are able to dream up experimental procedures that answer some pressing conundrum of the human condition in a fully scientific, reproducible manner.