any advice on bringing a kitten into a house with another cat?

ever since our kitty passed away our other kitty has been so sad and lonely we were going to wait but we decided it would be best to get him a new brother or sister sooner rather than later. we went last night and adopted a 4 month old kitten and as soon as our resident kitty smelled her he started hissing and growling. we are keeping them separated (the new kitty is locked in a room alone) for now, but do you have any advice for how to introduce a new kitten into the house?

Re: any advice on bringing a kitten into a house with another cat?

There are some things you can read on the internet with tips and advice.

My cousin did this. I know she kept them separated for a long time and then would start introducing them by putting the kitten (female) in a cage/carrier thing and allowing the other cat free (male) range. This offered protection and allowed them to smell each other. Her male cat would hiss and was not so nice at first.

I think she started with like an hour or two a day while she was home and then slowly allowed the kitten out of the cage and allowed them to interact supervised. And just kept gradually increasing the length of time.

It was a long time (a few months) before she left them home alone together in the same room.

Now they get along great.

I do think there are some difference depending if your cats are males or females - I would look online for additional tips.