Maternal Instincts? Pregnancy?

Question
My Female cat is about a year and a half and she is not spayed. I just moved in two new male kittens of questionable age and recently, she will not stop cleaning them (she will literally sit there for an hour if they'd let her#  - she is not in heat and she has not reacted this way EVER before with any of the cats she's ever lived with #she usually hates them, both male and female)....should i be concerned that she may be pregnant?

Answer
Lisa,

It sounds like she may be preparing to go into heat (Proestrus). This is the time in the cycle when the female begins attracting males but is not yet receptive to their advances. Estrogen is building up and she is preparing for ovulation. The female is extra affectionate at this time.

To be honest, anytime you have an unspayed female you should be concerned that she may be pregnant! If she were pregnant her nipples would be pink at about 3 weeks, and she would be putting on weight at about 5 weeks. I would get her spayed ASAP. Also get the male kittens neutered. Spaying and neutering helps with a LOT of behavior problems.

The grooming could be related to stress and/or an emotional issue. Have there been any major changes in the household or her routine besides the new kittens? Grooming (themselves or other cats) is a way for cats to relieve stress. Or there may be something about the smell of the new kittens that is attracting her or bringing out her maternal instincts.

Tabbi