Hi! Welcome to the Chinchilla Club and to the Wonderful World of Chinchillas!
The number of dustbaths can vary from one home to another. Dust baths, in my opinion, should be a minimum of 5 minutes and a maximum of 15 minutes.
In the summertime, they tend to get more fresh air from the out side, which is usually more humid. Chins need their dust baths every day or every other day in the warmer months of the year.
In the winter time, we tend to turn on the heat, which drys the humidity in the air ... in winter, as a general rule, they need dust baths only 1 or 2 times a week ... depending on the house they are in and if you do or do not run a humidifier.
How much they are handled is also a factor in needing/not needing baths as often or more often. Their fur can absorb oils and lotions from our skin, causing the fur to mat and/or attract dirt more than one that is not handled as much. It is always good to wash and dry your hands thoroughly before handling a chin ... not only for cleanliness, but also to remove any food or chemicals that could be on your hands. A bottle of instant sanitizer is always good to place near the cage ... for visitors to use when they come in to see your chins.
If a chinchilla is given dust baths to often, the skin can become dry and/or cracked ... this is usually evident on the feet and paws first. This can also set up chances of bumble foot, unless the shelves and floors are kept very clean.
What brand of chinchilla food are you using?
What are the floors, balconies and ladder's made of in your cage?
What size is the wire? (Distance between the wires vertically and horizontally?)
What size is the cage?
Were the two male chins living together before you purchased them?
What is their house made of?
Are they pulling their own fur, or each other's fur?
What kind of noise are they making? If you will check out the different chinchilla sounds on Michael's Chinchilla Home Page, I think you will find this site to be the best site I have found with the sounds and the explanations of each. It is at:
http://www.chinchilla-sounds.de/index_en.htm Pulling their fur out is not normal or good for them. Can you give a little more details about this, please. Are they fighting and/or biting?
Chinchillas need at least 30 minutes to an hour of free playtime out side of the cage on a daily basis.
Chinchillas love to be on a schedule ... just as you look forward to doing things you like, so do they.
Sorry about all the questions, but the answers will help.
Jo Ann