I tried to write a joke about a door...

but it was ajar.

What is blue but does not weigh very much?

Light Blue

What do you call a fish with no eyes?

Fsh!

My son was reading a book about volcanoes, and he came across a really interesting fact about how they erupt. He asked me if I knew how volcanoes tell secrets.

I told him they usually 'lava' to tell the truth.