Four weeks ago we took in a pregnant stray. We consulted our local shelters an no one could take her so we did. We had her originally in the basement in our home away from the hustle and bustle of the home so she could have a safe and secure place to have her litter. Here is where the problem lies we already had a year old adopted cat in our home who is also a female. We attempted to introduce them while the stray was pregnant but that did not work both cats hissed and wanted to go after one another. After the stray had the litter we wanted to jeep a closer eye on the young so we moved the litter upstairs, but in a seperate room. The desperate room does have a clear cat door but its sealed. We attempted to get the cats a little more use to each other by putting their food close to each other and that way they could also see each other. However that is it working at all everytime they see each other they hiss and meow. Not sure what the next step is. We feel bad for our cat, and the new litter.