Our natural instincts tend to be utterly reliable. But every so often they can drive us to do astonishing things.
Take the kestrel I watched feed its greatest rival the other day. Driven by its competitor's urgent, chick-like calls, it popped a morsel of food into its enemy's beak.
You may remember these two kestrels from my June blogs. The tension had been mounting between them as they fed at the bird table outside my kitchen - and then one of them, in spite of itself, did this!
To read more about this unusual story see my latest Yorkshire Post column