While looking for fungi the other day I came across a large number of Fly Agaric which all seemed a little worse for wear.

These are some of the better pictures. I looked in this area a few weeks back and found only one or two.
Questions...
How long does it take this fungus to grow ? It seems to grow very rapidly from first seen to fully grown.
What sort of insects/invertebrates eat these fungi ? Woodlice, slugs ?
I've also seen what looks like a Fly Agaric in late stages of life (no photo unfortunately) and it still has some white scales, but is almost white with just a very small hint of red. Is this correct or have I seen another type of fungus ? (Panthercap ?)