Minecraft Forums

I have been following and playing minecraft since before the arcade version. i have been watching minecraft videos for over a year. i like to think i know just a little bit about how the game works. i thought no mobs of any kind could spawn on half slabs. somehow i have slimes spawning in a slime chunk that is completely covered in half slabs. its sealed off from any caves and the entire floor is flat with half slabs but somehow slimes are still able to spawn. no other mobs have spawned just slimes. im confused? do slimes spawn on half slabs or is it a glitch?