A friend of mine had two kittens -- siblings, who were very close to each other. One of them was hit by a car and killed. I had adored this kitten, so in memory of her I did a chalk drawing portrait of the kitten, and brought it over to my friend as gift, about a week after the kitten had died. The surviving sibling had, during that time, seemed somewhat morose and unresponsive, but also kind of cryptic in the way that cats can be. Hard to read.

But when the surviving kitten saw my drawing, he began crying so piteously, reaching out and clawing towards the drawing -- and this went on for most of an hour -- that there was absolutely no mistaking the emotion behind it, and soon everybody else in the room was bawling as well. (Also, I was impressed that he responded to a drawing; it was a decent drawing, but quite abstract relative to (say) a photographic representation. Cats usually seem oblivious to photos in any case, and this is one of the things which confounds animal consciousness research: it's very hard to tell the difference between something that an animal can't do, and something an animal doesn't want to do. I suspect that most of the time, cats simply can't be arsed to process static 2d imagery, because what's really the point of doing so -- but in this case, an overwhelming emotional imperative overrode that natural disinclination, proving that both the cognitive and the emotional capacity is there.)

Anyhow, ever since witnessing that display of emotion, anybody who tells me that animals aren't conscious or don't have real feelings immediately gets ranked -- per my personal hierarchy of the spectrum of consciousness -- as being far below the level of that kitten.