Mushrooms: Why do they kill?

As daily updates about the 'mushroom murders' monopolised newsfeeds around the country, the What the Duck?! team started questioning the motives.  Not the human ones — the fungi ones.

Why would a mushroom need a toxin so powerful it takes just a few grams to kill a human?

And where's the warning?  Nature usually throws up alerts for poison, like bright colours or spots, but the death cap is pretty plain.

Why does a mushroom need such a deadly toxin anyway?

Featuring:

Tom May, senior principal research scientist at the Royal Bota...