No, they won't be Maggie - the right temperature to kill weed seeds would also kill the worms I'm afraid, assuming you're talking about a wormery.

As Bamboo says, Maggie ~ too hot for seeds is too hot for worms!! :)

Thanks for the response. I was aware that in an ordinary bin it was the heat that killed the weed seeds, but I was rather hoping that they would not survive the process of passing through a worm! Oh well, back to the drawing board!