Marnie Chesterton

known as Sagittarius B2, contains a vast amount of something called ethyl formate or ethyl formate, which is a key chemical that makes up the taste of raspberries, which, as we've learnt so far in this show, isn't actually a berry.

So, still to come on the show, vegetables that aren't, but that might be immortal.

That's coming up after this.

Hello, Lucy here, and it's time for this week's Unexpected Elements quiz.

The animal world is home to some fearsome creatures, but one in particular trumps the rest.

Mothers.

It's said that mums would kill for their kids, and in the animal kingdom, this is often true.

But mice mothers at least have the decency to give out a warning first.

Mice that are expecting or have recently given birth have a unique way of sending a message to strange male mice to warn them of the possibly painful consequences of coming near their kids.

So my question is, what form does this message take?

A. Banana-scented urine B. Orange-coloured sweat Or C. A circle of berries around their nest

That's how do new mice mothers warn male mice away from their babies?

A. Banana-scented urine B. Orange-coloured sweat or C. A circle of berries around their nest Have a think and I'll be back soon with the answer.

You're listening to Unexpected Elements from the BBC World Service, where this week we've been focused on the fruit and veg section of science, inspired by the headline of the loss of most of the prized Alfonso mango crop, which got us thinking sea cucumbers.

You may think this link is tenuous when I reveal that these are creatures, not one of your five a day.

Yes, they are in fact animals.

But I know you'll forgive us when you hear that, according to a new study, they might be immortal.

To tell us more, we're joined by Dr. Annie Mercier from the Memorial University of Newfoundland.

Annie, welcome to the show.

Thank you for having me.