Can I put my children on the deed to my house? The youngest is 18 years old. I live in the state of CT.

You can add any of your children to your deed. Assuming it is paid for with no loan. If there is a loan you will have to get the banks permission to change the deed.

I would ask why ? It can be risky to add people to the deed, and exactly how you do it, can decide many future factors.