Cat doppelganger? How can I tell which is which?

My brother let a stray inside thinking it was my cat, they both look exactly the same! I'm thinking about keeping this one but getting it in for a check up first. My cat (Weiss) hates collars so do you guys have any clue how I can make sure which is which? And yes, it's a stray. No. my cat is well kept not wild. YES. They both look EXACTLY similar.Cat doppelganger? How can I tell which is which?
Shave one of them. Or shave both of them, and then write their names on them.Cat doppelganger? How can I tell which is which?
The best thing is to put a collar on the stray, or put a collar on your brother's cat. Putting it on the stray would be better, since it goes outside you don't want people thinking it doesn't belong to anyone. Cats that hate collars usually get used to them fairly quickly. They'll put up a huge fuss for maybe 30 minutes and then go on with their life.



Also, all cats have different personalities, different meows, different walks, if you take some time to get to know these cats really well, you should be able to tell the difference without much effort.Cat doppelganger? How can I tell which is which?
Many cats have different personalities and tones in their voices. I used to have two black kittens, I could tell them apart from personalities and activity. One barely ever came out to play, while the other was always running around and enjoying itself.



Getting to the know the new cat may prove helpful, other than that I'm not sure how to help.



A collar on the new cat might be a good idea, but they always make me nervous. Many times my cat would come back into the house with branches or other things caught in her collar. It worried me that she would get caught and not be able to escape or get away.



Anyways, good luck on the identical cat problem!