The autonomous pet woohoo definitely keeps the game interesting. I had two generations of accidental kittens in the same household once. My sims adopted an adventurous cat who would leave the lot periodically. I forgot that doing that could result in kittens if the cat was not fixed and, of course, she wasn't. Thankfully, she only had one kitten, a girl. However, her daughter inherited her adventurous trait and the same thing happened to her. She also had one kitten, a boy this time. The family line ended with him because he never autonomously mated with anyone and I never directed him to.