Hello, Your baby is too small to form a habit right now but yes, check is important. Till the time permanent teeth doesn't come no need to worry. After the age of 6 years if the habit continues it needs habit breaking  appliance. About snaggling don't worry as of now. Still lot of changes will happen in teeth position.

Hello  , Welcome to PRACTO - This is your Dentist - I went through your query  . Thumb sucking habit is seen in many kids but once it becomes a habit that's where the problem arises. Since the kid is very young ,nothing to worry as its just the milk tooth  and has no effects on Permanent tooth . But if the habit continues , it can also affect the Permanent tooth . So when ever you notice the kid sucking thumb kindly remove to break the habit. Pacifiers (Soothers) helps alot  in breaking the  finger sucking habit. Since it too has a disadvantage of tooth misalignment ,should not be used regularly or continued for a long period. I hope it was helpful. Kindly post me if any further doubts or query and I will assist immediately and help in every possible way. Have a Good Day Thanks Alot.