If the brown/black beetle has a tan stripe across the back it is probably the larder beetle, another one of the dermestid beetles.
This very large and diverse group of beetles are specialist scavengers on dead plant and animal products. They evolved as nature's master recyclers that help breakdown and decompose dead plant and animal tissue. If you think about it from the beetle's point of view a piece of wool cloth (or animal carrion) or a dog biscuit (or cache of seeds) is just another dead animal or plant, and something good to eat.
When you find the beetles indoors it usually means there's an infestation somewhere in the house. The beetles are harmless but obviously if the infestation is large damage can be done to your stored food or natural fabrics.
See the pages cited above for ways to detect and manage infestations of stored product beetles. Once the infestation is found and cleaned up you can treat the surrounding area with one of the new Botanical Insecticides to eliminate any stragglers that may have been missed.