If you decide you want a rooster, one will be plenty for your flock with your stated goals. You said you want to hatch chicks so you will need a male or you will need to change your goals. If you hatch chicks you will get males. Do you have a plan for what you will do with them?
You can add a male at any time. If you have an all female flock, one of the easiest integrations is usually to wait until they are laying or older and add a mature rooster. probably a year or two old. If one of the chicks you have now is a male you can let him grow up with the rest. The downside to this is that you have to watch them go through puberty. Sometimes this is fairly uneventful but usually it can be very dramatic. A cockerel's hormones can cause hm to get out of control when trying to dominate the others. It can get brutal and vicious, be very hard to watch. This phase is when many cockerels literally lose their heads and become dinner.
If you decide to add a cockerel chick when your girls are older, do not try to add only one. Don't do it even if it is a pullet. Single chicks or even older chickens can be hard to integrate. Always add at least two together and three or more is better. If you try to add two and one dies you are back to a single chick or chicken. Some people prefer to add a cockerel this way but I don't see any real advantages. You'll find that a lot of this stuff is personal preferences and individual opinions, sometimes based on our experiences which can be very different or sometimes based on what we read.
One common misconception people have on this forum (not necessarily limited to newby's) is that behaviors are always this or never that. You are dealing with living animals, about anything can possibly happen. I raise cockerels with my flock every year. Sometimes it gets really rough, sometimes there isn't much there. Every three or four years it gets rough enough that I lock up several cockerels isolated from the flock until they grow to butcher size. That means the other years it doesn't get that bad.
Another part of this is perception. For some people certain behaviors are totally unacceptable. An extreme example is that if a cockerel force mates with a pullet it's off with his head. Or if two chickens, either male or female, skirmish to determine the pecking order it is a disaster. I'm more laid back. In my viewpoint chickens are going to determine which is the flock master and they will determine the pecking order. Sometimes determining the pecking order involves pecking or more. As long as no one is getting hurt I tend to let them be chickens and work it out themselves. We sometimes refer to this is to not interfere unless you see blood. I don't go that far, sometimes I interfere before it comes to that, but I am not quick to interfere.
I've never had a pullet injured during this phase, others have. I did have one cockerel kill another during this phase, but only one. Remember I do occasionally interfere but I waited too long in that case. I think one of the advantages I have is that mine have over 3,000 square feet available to them outside and I have weather where they can be outside practically every day all day when they are going through this. I find that bad behaviors are magnified when they are crowded.
Something else. Each chicken has its own personality and each flock has its own dynamics. Those can change as a bird matures or if you add or remove a flock member. Any chicken of any sex and any age can possibly be a brute and a bully. I had a 2 week old chick kill a sibling while the broody hen watched. About anything can happen with living animals.
All the above is about adding a male to your flock. Now to get to the elephant in the room, the danger to your children. I am not going to argue that a rooster is not a danger to your children or even an adult. Mature roosters have spurs that are a dangerous weapon. Any cockerel, pullet, rooster, or hen has sharp claws that can rip flesh. They have a beak that can cut a frog into bite sized pieces or take out an eyeball. The potential is there. Yet many people cuddle with their chickens and encourage them to sit on their shoulders within reach of their eyes and encourage their kids to do that.
Roosters are programmed to protect their flock. Broody hens are programmed to protect their chicks. If someone picks up a broody hen's chick she could easily do real damage to them, especially to a child, yet some broody hens allow people to pick up her chicks. Each chicken is different with its own personality.
Some roosters are human aggressive. There are different theories on here on how to raise one to be non-human aggressive. From what I've seen any of those methifs work some of the time but any of them can fail. There is the debate if it is nature or nurture. Are they born that way or have they been trained that way. I think it is a bit of both.
People have been keeping flocks of chickens with roosters for thousands of years while raising kids. I grew up on a farm like that. Many of my relatives lived on farms like that. There is no doubt roosters could attack kids but it just didn't happen that often. None of these relatives penned their chickens, they all free ranged. And where those chickens stayed was typically where the kids did not play. The kids gathered eggs and had other chores or jobs in those areas but they did not have a lot of interaction otherwise. I don't know how you plan to free range your chickens or how much interaction your kids will have with the chickens.
I remember a thread from several years back on here where a father thought it was cute the way his 4-year-old was chasing the hens but did not think it was as cute when the rooster started attacking his kid every time the kid stepped outside. That rooster went from being great to where he had to go.
I'm not going to say there is no danger to your kids from a rooster even if you do everything "right", whatever right. If he shows any human aggression I would not have any patience. In my opinion, that risk will not change whether you bring in a mature rooster or raise a chick with the flock. Also my opinion, the more your kids interfere with the flock the higher that risk is. People around the world have been making this work for thousands of years. To me the big difference now is that they are more pets than livestock and are treated differently.
You can add a male at any time. If you have an all female flock, one of the easiest integrations is usually to wait until they are laying or older and add a mature rooster. probably a year or two old. If one of the chicks you have now is a male you can let him grow up with the rest. The downside to this is that you have to watch them go through puberty. Sometimes this is fairly uneventful but usually it can be very dramatic. A cockerel's hormones can cause hm to get out of control when trying to dominate the others. It can get brutal and vicious, be very hard to watch. This phase is when many cockerels literally lose their heads and become dinner.
If you decide to add a cockerel chick when your girls are older, do not try to add only one. Don't do it even if it is a pullet. Single chicks or even older chickens can be hard to integrate. Always add at least two together and three or more is better. If you try to add two and one dies you are back to a single chick or chicken. Some people prefer to add a cockerel this way but I don't see any real advantages. You'll find that a lot of this stuff is personal preferences and individual opinions, sometimes based on our experiences which can be very different or sometimes based on what we read.
One common misconception people have on this forum (not necessarily limited to newby's) is that behaviors are always this or never that. You are dealing with living animals, about anything can possibly happen. I raise cockerels with my flock every year. Sometimes it gets really rough, sometimes there isn't much there. Every three or four years it gets rough enough that I lock up several cockerels isolated from the flock until they grow to butcher size. That means the other years it doesn't get that bad.
Another part of this is perception. For some people certain behaviors are totally unacceptable. An extreme example is that if a cockerel force mates with a pullet it's off with his head. Or if two chickens, either male or female, skirmish to determine the pecking order it is a disaster. I'm more laid back. In my viewpoint chickens are going to determine which is the flock master and they will determine the pecking order. Sometimes determining the pecking order involves pecking or more. As long as no one is getting hurt I tend to let them be chickens and work it out themselves. We sometimes refer to this is to not interfere unless you see blood. I don't go that far, sometimes I interfere before it comes to that, but I am not quick to interfere.
I've never had a pullet injured during this phase, others have. I did have one cockerel kill another during this phase, but only one. Remember I do occasionally interfere but I waited too long in that case. I think one of the advantages I have is that mine have over 3,000 square feet available to them outside and I have weather where they can be outside practically every day all day when they are going through this. I find that bad behaviors are magnified when they are crowded.
Something else. Each chicken has its own personality and each flock has its own dynamics. Those can change as a bird matures or if you add or remove a flock member. Any chicken of any sex and any age can possibly be a brute and a bully. I had a 2 week old chick kill a sibling while the broody hen watched. About anything can happen with living animals.
All the above is about adding a male to your flock. Now to get to the elephant in the room, the danger to your children. I am not going to argue that a rooster is not a danger to your children or even an adult. Mature roosters have spurs that are a dangerous weapon. Any cockerel, pullet, rooster, or hen has sharp claws that can rip flesh. They have a beak that can cut a frog into bite sized pieces or take out an eyeball. The potential is there. Yet many people cuddle with their chickens and encourage them to sit on their shoulders within reach of their eyes and encourage their kids to do that.
Roosters are programmed to protect their flock. Broody hens are programmed to protect their chicks. If someone picks up a broody hen's chick she could easily do real damage to them, especially to a child, yet some broody hens allow people to pick up her chicks. Each chicken is different with its own personality.
Some roosters are human aggressive. There are different theories on here on how to raise one to be non-human aggressive. From what I've seen any of those methifs work some of the time but any of them can fail. There is the debate if it is nature or nurture. Are they born that way or have they been trained that way. I think it is a bit of both.
People have been keeping flocks of chickens with roosters for thousands of years while raising kids. I grew up on a farm like that. Many of my relatives lived on farms like that. There is no doubt roosters could attack kids but it just didn't happen that often. None of these relatives penned their chickens, they all free ranged. And where those chickens stayed was typically where the kids did not play. The kids gathered eggs and had other chores or jobs in those areas but they did not have a lot of interaction otherwise. I don't know how you plan to free range your chickens or how much interaction your kids will have with the chickens.
I remember a thread from several years back on here where a father thought it was cute the way his 4-year-old was chasing the hens but did not think it was as cute when the rooster started attacking his kid every time the kid stepped outside. That rooster went from being great to where he had to go.
I'm not going to say there is no danger to your kids from a rooster even if you do everything "right", whatever right. If he shows any human aggression I would not have any patience. In my opinion, that risk will not change whether you bring in a mature rooster or raise a chick with the flock. Also my opinion, the more your kids interfere with the flock the higher that risk is. People around the world have been making this work for thousands of years. To me the big difference now is that they are more pets than livestock and are treated differently.
