That can happen under certain circumstances, usually with villager-initiated breeding. It's typically caused when one villager in a "pair" gets interrupted by another villager and, being sidetracked, never makes it to the hut. It can also happen if one of the villagers is elderly and makes it to the hut long after the other has left. There have been some really funny discussions and breeding stories in this forum since the release of Village Sim last year.

One particularly funny comment was:
Quote:
Hey now!!! All they ever do is GO INDOORS. RIGHT? They just go indoors. Then a super-fast stork brings the baby to the nursing mom, and quickly disappears.