Yes. About 80% of cavities on baby teeth happen in between the back teeth where the floss gets. Regular brushing is important as well, but floss them as often as you can. I personally have 3 kids, aged 2, 4, 6, and realistically floss their teeth about once a week. More would be better, but anything is better than nothing. I find it nearly impossible to wrap traditional string around my fingers and get it in their mouths though. My personal recommendation is Listerine’s “Ultraclean Access Flosser”. I love these things. I bought one for each kid and color coded it with tape. Get one or two for yourself as well. They’re fantastic. Rinse the strings off until they break or look bad, and then change them out. You can get them off Amazon, but they’re cheaper at the pharmacy.