A Twitter follower asks: "What do you do when you see your kids pick up your bad habits that you don't want them to have?" (That question could cover a lot of ground, so the follower agreed to narrow it down to something like biting your nails.)

I asked Molly Brown Koch, a local parent coach and author who has answered questions about kids using public bathrooms and about dealing with a young hitter, to tackle this one.

She wrote back that the solution -- and the adults may not like this -- is for the grownup and the child to have a talk and agree to kick their bad habit together. Even a child as young as 3, she says, can help brainstorm solutions if asked.

"Children are little 'strangers in a strange land,' they study us to find out how to be, what to  do, how to do it, and because they love us so much, we are their most important role models," Koch writes.  "If the child is old enough to understand, you can explain that you have been doing something for a long time and are ready to get it under control.  A brainstorming session about ways for you to stop the habit can be both enlightening and fun.  Let the child be part of the solution, and be partners in both your efforts to end the habit.

If it's not so easy for the child to give up the habit, don't point out his failures, Koch writes. "Nothing works as well as praising children for their efforts, for their persistence, for their strength of character, and celebrating with them when they succeed, day by day," she says.

It's appropriate to offer a reward to the child for finally kicking the habit -- but make it a special outing with you, Koch advises, rather than a toy.