Where has my female cat gone

Yesterday I found two male neighbour cats hanging around my cat. They wouldn't leave her alone and she was hissing at them. One of the cats is black and started chasing her. Since then I haven't seen her. The black cat now constantly comes around to our house and starts meowing, as if he is looking for her. What's going on? Has something happened to her? Why is the black cat meowing 24/7? What should I do?

If your cat has not been spayed, it is more than likely she is in heat. The cycle for cats in heat is: through early summer-early fall, they can get in heat. The closer it gets to the ending point, the less likely she is to get in heat. If your cat in fact was in heat, she will probably not come back.that is the bad news. I suggest you put up signs and try everything to get her back. I imagine your cat is in good health. If you do find her, I sugggest a vet appointment, spaying if you can at this time, and bring her into the house as an indoor only. That is the first theory. I must admit that the black cat is acting strange. Usually when a cat is in heat, they tend to meow a lot, sometimes bleed a little, and act very friendly. Male cats smell this and are attracted to find the female in heat. If it turns out your cat was a male, it would make more sense as to why it disapeared, and why the black cat is meowing. My best advice is to: Talk to your neighbors; if they have cats, seen your cat, and what you can do about it, talk to your vet; see what advice they have, and three, look for your cat. Although I am not sure, I believe your cat will be ok, and show up after awhile. Try putting food out for her, and if the other cats come, then either: a) capture and take to vet b) scare away c) leave be. I wish you must luck in finding your best friend.