Derek Mooney

And the reason for that is they can't have that red breast because if they had that red breast, both the mammy and daddy would attack them.

But the mam and the dad are feeding them?

Absolutely, yes.

They're not very social birds.

If you think another small bird that you'd have in the garden, say the blue tit.

The blue tits are much more social than the robins.

And a good example of that was back in the 1930s or so when blue tits in Southampton in England...

They discovered this trick of going to milk bottles, they used to have milk bottles in those days, and they could peck open the top of the cap.

The foil cap.

The foil cap, yeah.

And they were doing that to get at the cream.

It's not milk that's in the bottle, it's milk, full milk.

But at the top of the full milk, there's cream.

They can't drink the milk themselves because they're lactose intolerant.

It makes them very, very sick.

But they can take the cream.

And they can digest that.

Isn't that extraordinary?

Yeah.

And then, you see, because the blue tits are a more social bird, they've actually passed that on to other blue tits.