It depends on the dog, usually you can as long as you don't spend 24/7 with the pup
It depends on the chihuahua. About 6 weeks.
A puppy should never be removed from its mother prior to six weeks, and eight weeks is preferable. The more mother's milk it receives as a puppy from a healthy bitch, the healthier the puppy will be.
Go to the vet
No, that is too young. The pup needs to be with its Mom for at least 8 weeks. Anything else is just irresponsible on the breeders' part.
The size of a meerkat pup that is three weeks old is about three inches tall, so a newborn pup would be slightly smaller.
Answer 1: Are you sure it's biting? Maybe she is carrying the pup in her mouth (which isn't a bad thing), or grooming the pup(which you shouldn't mind), or taking care of bugs or other skin things on the pup (which then you should take the pup to a vet). You should check and see if she really is biting the pup. Answer 2: If the mom is biting the pup, 1st check with the vet to see if the are bugs or skin problems with the pup. The mom could very well be trying to cure the pup. Answer 3: Check the vet to see if the mom has any mental problems. Is the mom acting out of the ordinary?You should see. These are not all the answers, but these are all I can give you. Wish you luck!
Your pup can be weaned as young as 4 weeks of age. Ideally the pup should remain with his or her Mom up to 8 week of age but if she is ignoring the pup, then wean the pup. Do not let the pup nurse off of its Mother, so her milk can dry up. Feed the pup a good name brand dry puppy food. Soften it at first with warm water, feed 2-3 times a day, all that it can eat within about 10 minutes, pick up any left over food. As the pup gets older, feed it the dry puppy food without it being softened with water.
the pup gets bigger
You're not SUPPOSED to, but the mom might count heads and become upset. It is best for the pup to stay with its mom.
When you know a dog gave birth and if you are absolutely positive it is the first pup, then bring mom and pup to a box lined with a layer of newspapers and old but clean rags. Other than this one time, don't touch the pup again. Put mom and pup in the box in a quiet corner.Watch mom and make sure she has another pup within 30-60 minutes. IF not, or if mom seems in distress, take her AND the first pup to the vet (pup will need mom so do not separate them).Labor should progress every 30-60 minutes or so. Mom will lick her privates and you may see the area begin to bulge. Talk quietly to her, but let her do her job. She should push out one after another (with time in between).NOTE: If you don't know if it is the 1st born and your dog is outside with the puppy, you may need to wait to bring her in until she leads you to the rest (if she had any others).
because of your mom
It's a good idea that the mother keeps nursing her young pups until the pups are 6 to 8 weeks old. This way puppies will get a good start on life.