Secondly, they aren't white.. While some double merle dogs are almost pure white, they can go the complete range all the way up to a dog that you would think is a just a normal merle (most fall somewhere in the middle).
In between five and six months, your baby usually starts to sit up with your help, holding his head in an upright position, keeping the back straight. He may even be able to sit for a second or so without taking any assistance from you, before toppling down after a while [1] .
In most cases, babies begin to crawl between the ages of 6 to 9 months or when they are able to sit independently, and have muscles in the neck strong enough to keep their head up and muscles in the legs, arms and back strong enough to keep the weight of the body when on their hands and knees.