I think you sit them down and explain to them about where dad is. I would tell them because if a family member or a cousin tells them its going to hurt them. My kid later found out that I had to do week-ends in jail for a ticket. All is good because they are old enough to understand. Tell so they understand and its not their fault.

They may be too young to understand. eventually, yes, they should know but chances are it may hurt them because that is a part of them.

If they know, then everyone at school will know. You may not want to have to hear from other parents or suffer the social stigma that may go with that too.

I say, let sleeping dogs lie. They are used to him not being around, anyway.

how old are they first and would they understand

How much has this worthless piece of sh*t have in your childrens life? If none, then don't say anything.

Believe me, kids figure it out. If ole' sh*t isn't in the kids life, they move on. I'm a former youth minister (and would love to do it again) and kids like SIMPLICITY. Black or white in concepts with kids.

What you have to worry about isn't the sh*t in jail, but how the kids feel right now about their relation with S*. If it's close, then... I would say, "Look, Daddy love you but there's stuff in his life. It has nothing to do with you, but there's stuff. I'm here...and I love you."

Kids don't figure our stuff...they need routine, schedule, someone to apply this with love and just to know they're the best. Don't put your adult stuff on them because they won't understand.

I can go on forever...about divorce, whatever. I saw the world through the eyes of teens and believe me, they don't see it like someone who's your age. They need love and support.. "This is Parent X and they're in jail, but don't hate them...wait. I'm here."

That's it.

Yes tell them. But be prepared for disappointment and anger issues. Children pay (in actions) for their parents actions. In other words, children may act out instead of talking.
Cindy52