Locks are used all over the world to stop things being stolen.

You can get locks for your bike, locks for your house - you can get locks for almost anything!

An old lock-maker's saying is 'The bigger the thing, the bigger the lock'.

And if you think about it, it makes perfect sense! It seems that lock-makers aren't as stupid as they look.

The biggest lock, therefore, must be for a very large object!

You know what I'm thinking:

A glacier!

So if you want to lock up a glacier, you'd better hire the biggest lock, wherever that is.