As far as I can read on the wiki, mobs spawn ON solid blocks, IN air blocks.
That would rule out mob spawn on any sort of small item-fille block, a block which is not completely air.
However, I believe I have seen mobs spawn on carpet-covered blocks. I have also seen mob farm dsigns where pressure plates or tripwire is used to let mobs trigger pistons.
A monster farm with pressureplate-activated traps sound cool. But will the pressure plate prevent mob spawn in that block?
Also, I might want to place some brown mushrooms, possibly a redstone torch, in order to have a tiny bit of light there. Will they prevent monster spawn?
Anybody know this? Thank you in advance.