Babies are born with an instinct to survive. This shows up in the strong sucking reflex babies have at birth and it shows up in the way the mouth is exceptionally sensitive at birth. As your baby grows into toddlerhood, the mouth remains sensitive. That is why little ones are forever putting things into their mouths, touching them or tasting them or chewing them. Mouthing things is a major way children of this age experience the world, so this is one reason why your child is putting her hands into her mouth. I suggest you avoid taking her hands out of her mouth. Instead, try distracting your daughter into some activity when you think she has had her hands in her mouth for too long a time. Another reason your daughter may be putting her hands in her mouth is teething. Is she putting other things into her mouth besides her hands? If so, she may be teething.
A third possibility is that your daughter may be feeling tense and putting her hands into her mouth in order to soothe herself. Children are very sensitive at this age to any conflict and lack of harmony in the home. I remember one little 2-year-old saying to her mother, “Why you no like him?” This child had picked up on the conflict going on between her mother and her father. So if there are problems at home, your daughter could be reacting and you will have to take steps to improve the atmosphere. Children at this age normally do not develop a habit of biting their nails. I recommend you consider these possibilities to determine what is going on, so you will best know how to handle your toddler.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.