The scientists think the co-ordinated behaviour may be a strategy for avoiding predators rather than to corral the krill.

BBC: NEWS | Science/Nature | Penguin-cam snaps amazing images

Driving the strategy of all these firms is the shifting behaviour of consumers. eBay's business, in particular, has been moulded by its users.

ECONOMIST: eBay

Lord Ramsbotham argued that because no-one in the prison service was responsible and accountable for young people, there was no overall strategy aimed at challenging their criminal attitudes and behaviour or preparing them for a future free of offending.

BBC: Ex-prisons chief: Prison is failing young offenders