[JM]

There was a program on TV, a number of years ago now, where a group of crows in Japan had learnt to crack nuts by waiting at a zebra crossing (or the Japanese equivelent) for the green man, then running out placing their 'nuts' on the road, scurrying back. After the traffic had started again, the nuts got squished, the green man came on again and they would scurry out and eat the nuts...... very clever!