Hi Danny
Great that you have asked this
Yeap i agree with the others that it's the start of sexual behaviour and will stop a little while after the lads have been "done"
If with the girls you leave them unspayed and they are let out they can get preggers at a very early age (from 5-6 months) and very quickly so i def would think it would be sooner rather than when they are older that they would get pregnant.
Just wanted to give ya a bit of info for females, so you can make a good decision for them and your family
Female cats - 'Shouldn't we let her have one litter?'
It is a complete myth that a female cat should be allowed to have one litter. There is no biological or psychological benefit to the cat whatsoever. If you allow your female cat to have a litter, and manage to find homes for the kittens, they have then used up homes that kittens sitting in a rescue centre could have had, which may then end up being destroyed.
Many female cats come into season, get chased far from their home by un-neutered males and end up completely lost, pregnant, and living on the streets. This is how feral cat colonies are formed. They struggle to survive, often hungry, and frequently becoming sick or injured.
Many stray, un-neutered males carry the FIV virus, and female cats are often infected if they are bitten during mating. Males often infect each other with FIV or feline leukaemia when fighting over a female.
A female cat should be neutered (spayed) at 5 - 6 months but can be neutered at any age. Neutering can be done earlier, provided the kitten is in good health, but you will need to be guided by your vet. To prevent unwanted litters, your kitten should be kept indoors until it is neutered. Even if your cat is to be kept as an 'indoor cat', it is kinder to neuter her, as she will still come into season, which is very frustrating for her and for you. Un-neuterd females are also more at risk of developing cystic ovaries and the potentially fatal pyometra.
Also here are some helpful hints and insites in to why it's so much better to have the girls Spayed too before they get preggers
TOP 20 REASONS WHY TO SPAY YOUR CAT
1)You will help maintain the cat overpopulation low
Each year thousands of kittens are born. In order to understand the cat overpopulation, simply think that each unspayed cat may have up to 8 kittens 2-3 times a year. Some of these kittens will die from natural causes or accidents others will be brought to a rescue. Being so numerous unfortuantely a large percentage will end up Put to sleep.
2)Your cat will not have heat cycles again
A cat's heat cycle is not just a cycle. The hormones create major behavioral changes. If you hear a cat cry out in the middle of the night very likely it is a female in heat. Cat's in heat tend to be very vocal and clingy. They may simply drive an owner nuts. This will not occur any longer if your cat is spayed.
3)Your cat will live longer and healthier
Just the simple fact of having several litters a year may play a big role in reducing your cat's health and life expectancy.
4)No more tom cats around
Other than your cat meowing desperately looking for a mate, you will have to deal with the long line of Tom cats presenting to your door. Your female cat will not need to log on to E.Harmony to find a mate. Her cries and her urine smell are sufficient to make her the most popular gal in town.
5)No more roaming
Even female cats tend to escape when in heat and may not show up for a day or two. By spaying, your cat will be less likely to make it through the door looking for a mate.
6)Less risk of getting FIV/FELV
If your female cat goes in heat she may roam around the neighborhood and be an easier target of many serious diseases that may be caught by getting in contact with tom cats. There are various diseases that can be easily be caught by bites. Because tom cats give a "love bite" when they copulate, if the bite is given with too much passion it could transmit deadly disaeses such as FIV and FELV.
7) No venereal diseases
Even though not that common, cats may also get sexually transmitted diseases. Another good reason to spay!
8)Your cat will have a better disposition
With all the hormones out of the way, your cat will be much calmer and easier to deal with. Some cats even become sweeter and more cuddly.
9)Your cat will be less likely to hurt or get hurt by other cats
If you have ever watched the process of a cat's courtship, you will notice it is not a mellow process. Male cats will follow the female in heat and attempt to mate even with the use of force. The female cat may defend herself with teeth and claws if she is not ready. The whole process can turn out pretty ugly for both your cat and others cats fighting over for her. Not a nice sight indeed.
10)Lower chances of getting mammary cancer
Ideally, spaying before the first heat will dramatically lower the chances of getting mammary cancer. However, even spaying at a later time will contribute to lowering the chances.
11)Spaying reduces chances of tumors of the uterus and ovaries
With no more uterus and ovaries which are taken out during the spay procedure, of course the chances of getting tumors of these organs are close to none!
12)Spaying reduces the chances of infections of the uterus
Same here, with the uterus removed your cat will not be prone any longer to a dangerous life threatening uterine infection called Pyometra.
13) Spaying will save you money
Spaying is a one time surgery that will last a lifetime. It will save you money in the long run because unspayed cats are more prone to illnesses and caring for a litter may easily cost a lot more than the spay procedure itself.
14)Spaying will avoid birth complications
Birth is a natural event but the risk of complications are always there. Are you ready to take over the fiancial burden of having your cat seen on an emergency basis should a complication arise? Birth complications are not that rare and they can be fatal to both mom cat and kittens
15) No need to rehome kittens!
With rescues over full, it can turn out to be challenging finding a home for a litter of kittens. Of course, it would be terribly irresponsible to leave a boxfull of kittens in front of vet hospitals or shelters,yet it does happen quite often!
16) If your cat just mated or is in heat she can still be spayed
Ok, your cat went in heat, and you noticed it too late and she is already hanging out with a boyfriend. Good news is that you can still spay her and spare her from having kittens. However, there may be an extra charge for the spay procedure for cats in heat or pregnant.
17) No false pregnancies
Some cats that are not mated when in heat may resort to simulating a pregnancy. This behavior seems to increase as the cat ages. This annoying behavior is avoided with spaying.
18)Spaying is a relatively safe procedure
Spaying is a routine procedure, it has a high success rate with low percentages of complications. While it is true that as any surgery there are risks, the benefits highly outweigh the risks.
19) You can spay as early as four months!
It is a fact that small kittens recover more swiftly than older aged kittens. If you have a four month old kitty have her weighed, chances are she can already be spayed cutting recovery time in half!
20)You will set an example
Last but not least, by spaying, you will set an example for your community. You will educate and spread the voice of the many benefits of spaying.
Just a few bits of info for ya so you can decide whats best for you and your wonderful family