Children in the Musjid

Children standing in the adults' saffs if they are misbehaving

Q: Is it correct for a person to keep his sons behind him in the masjid - away from other children as these children are causing a disturbance in the back. Some children hit others. 

What will be the correct age to bring children to the masjid? Any guidelines regarding the children's saffs as some mention that the children can stand in the adults' saffs if they are misbehaving. 

Please clarify with guidelines for our masaajid.

Children standing next to their fathers in the saff during salaah

Q: I wanted to ask the mas'alah regarding children standing in saffs with the men. I always knew that small boys should stand behind the saffs of the men. However, I have noticed a trend of small boys standing next to their fathers.

It just worries me and I am inconvenienced at these small boys standing beside me in the saff. Please advise and guide as to what is correct according to Shariah.