Enemies Spawning On or Phasing Through Traps?

Sadly I have no receipts, but I have noticed instances of enemies that are asleep spawning on the same tile that traps are on. Is this intentional? Additionally, I was in a fire trap room in the sewers and a rat ran at me, I one shot it with ranger bow, and when it dropped coins on death it triggered a fire trap it was on. I don't believe it spawned there, so I don't think it triggered the trap when it ran over it. Has this happened to anyone else?