I had a dream last night that I think might be taken from a book I read long ago, but I don't remember it. Here's some things that happen in it, and these memories might not be entirely correct:
>there is a group of at least 4 children, aged from 10 to 14 I think
>they go into the forbidden caves to have an adventure
>they get attacked by trolls and retreat
>(not sure if this happens before or after the trolls) the habitat of the subterranean mice gets invaded by the cats, who in turn get invaded by some larger animal. However, the group of kids manage to set everything right
>they go into the caves again, but get separated. The story follows each one separately from now on >one of the boys is driven deep underground, where he encounters some blue ant-like creatures. They challenge him to walk through the following passage without stepping on any of them. They are arranged in complex patterns. He steps on some and receives psychological torture
>another one of the boys goes even further underground where he hallucinates. The narrator says something like 'the boy [who met the ants] wouldn't even begin to understand'
Does anyone know what book this is?