[jaybee]

I have a pair of cats whose mother was a stray. The humane society insisted that they are brothers, but they they don't look anything alike. I've always wondered if they had different daddies.

[HairOfTheDog]

Dogs and cats both release many eggs and can be impregnated during any number of breedings during the heat cycle. It would not be uncommon for there to be different fathers in an free-roaming situation.

[muggs]

They probably are from different daddies. A litter of kittens often have different fathers.

[Yaelle]

I've always wondered if they had different daddies.

While cat litters can have widely differing looks among cats that have only one father, if the stray mom was out free during her heat, she was undoubtably "had" by a few males over that time period, and the kittens could well be from different fathers.

And, yes, this is possible in humans, if there is more than one egg released, and more than one guy in the, er, picture.