Big Question: How many animal species are there?

There are lots of animals on our planet, but just how many species are out there across the globe?

That's this week's Big Question from Hamstel Junior School.

We've asked wildlife expert Tom Luker to answer it for us.

And if you liked this, why don't you check out some more Big Questions:

Big Question: Why do birds fly south for the winter?

The Big Question: Why can't penguins fly?

If you've got your own Big Question you would like us to answer get in touch!