Thumbsucking: should you force kids to stop?

I have five-year-old twin girls who have sucked their thumbs since they were three months of age. Now that they have entered kindergarten, I feel it is time to start encouraging them to stop. They usually suck their thumbs when they are tired, upset or watching TV. Do you have any suggestions?

Thumbsucking serves as a way for young children to comfort themselves or to relax and unwind. In fact, it is relatively benign and poses no significant health risks.

Many children give up the thumb during the early school years, in part as a response to peers and the desire to be a big boy or big girl who fits in. I suggest that you ignore the thumbsucking. Your daughters will give it up when they are ready to do so. For now they are telling you that they still need to suck on their thumbs.

What you have in your mind?