John Burnside said this quote

When Mother had told me that animals found quiet, unexposed places to die, I had always imagined they knew they were dying, and accepted it, almost gracefully. Now I saw that this wasn't so at all: they crept into corners in the hope of surviving, they only knew they were weakened and exposed, easy prey, and their instinct was to find a hidden place and try to outlive whatever it was they were suffering. It had been a mistake to imagine they wanted to be alone, to die in peace. Animals have no knowledge of death; for them, death is the unexpected end of life, something they resist by instinct, for no good reason. In that sense, their existence has an almost mechanical quality.