male aggression

ok cloud got out last night and was out for about six hr around 4:30 this morning we heard him and spike going at through the screen so we let him back in and since spike has be having a fit to the point that i have had to seperate them they are both inside cats and cloud getting out was an accident how do i get the aggression to stop i have to small children and i don't want them to get hurt by my furbabys

ok here is an update while i was at work cloud has attacked my 4 yr old son and my husband i am at a loss as what to do i have bben keeping him confined to my bedroom untill we figure out what to do if he won't stop attacking people i might have to find a new home for him
if any one has an advice i would gladly take it

i called the vet and he said that if he is attacking my children that i might be better to place him in a home where there would be no children and just him because cloud has attacked my son he said that we are taking a chance that he will attack my son in his sleep and do even more damage
so i am now looking for a new home for cloud

How old is Cloud and how long have you had him for? What about the other cat Spike?

cloud was born last sept and i have had him since birth spike is will be 2 in oct
but spike is a registered therepy cat for my bipolar and we kept cloud as a companion but he is becoming more and more agressive and i am afraid for my children and his agressiveness is something i have been ignoring because i didn't want to have to give him up the vet said i could give him drugs but i don't feel that drugs are the answer he said that it is most likely that cloud can't handle the constant affection that my kids give him and that he is getting really stressed out he suggested that i try and find him a home where it will be just cloud and only cloud

Some cats do need to be only cats. I am assuming Cloud is neutered. Also, with his name - is he a white kitty? Is there any possibility there is a hearing problem?