What is the definition or description of: baby mouths objects?

Puts things in mouth: As infants develp, they first become aware of eye contact, will focus and eventually maintain eye contact and turn the head. The hands are often tightly fisted, but by 4 months, an infant will start to look at his hands and bring them to the mouth. After that, reach for objects and put them in the mouth. By 6 m, bring feet to mouth as well. Putting objects in mouth is normal until 2-3 years.