My dog just had puppies 2 days ago and there are so many flies around them. They are mostly around her tail. Is this bad for the puppies? What can I do to get rid of them besides taking them inside?
This is a potentially dangerous situation. Think for a moment where flies usually collect... it's around rotting biological matter.
If there are feces or waste from the birth clotted in the fur of your dog that attract the flies, carefully cut the soiled fur away and clean your dog. Clean the surrounding area as well if there is any biological matter lying around.
If there are no feces or other obvious causes for the flies, you have to take her to a vet. She might have an infected wound or her womb didn't clean out all of the placenta. Something must attract the flies and whatever it is, it's not healthy for your dog.
Keep in mind to take the puppies with the mother to the vet. They should not be seperated for too long to avoid stress.
Please do not spray insecticides or anything similar. The flies are just the symptom, you have to find and remedy the cause.