domestic cat meets feral cat

Question
hi:

i adopted a shelter cat, (female, spayd, 6yr, 5+lb).  she is very sweet an affectionat.  she has, however, discovered the great outdoors much to the chagrin of many small creatures (but, that is another story).  i would prefer to keep her inside, but that is a virtual impossibility.

tonight, she was lying in the window and started yowling, literally screaming(scared the heck out of me); going from window to window, tail swishing hard.  i grabbed a flashlight and saw a cat under window outside - feral.  

obviously, my desceptively sweet little kitty is aggressive and, apparently territorial.  ok, so now, if she goes out, will she try and find this feral cat?  if so, ?  

thanks in advance, christie

Answer
I would trap the feral and get it fixed, first of all.  Once the feral is fixed it will be far less aggressive.  My cats do fine with my ferals.  I actually have an in-and-out house feral right now!!

Typically cats will protect their territory, but not seek out others to be aggressive towards.  But for the safety of everyone, get the feral fixed.  Most areas have low cost spay neuter events and some vets charge less for ferals.  Put an ad on craigslist.com and check listings there.

Good luck!
Amy