There's a bug with wild puft that they sometimes stop moving after inhaling and before excreting. They will then literally stay like that until they die. Neither reproducing an egg or excreting. Doesn't matter what the type of puft (I've had regular and dense do it). The only work around so far is to have a dup move the puft. Which is annoying since I have to keep coming back to check on the pufts.