Mice are a nightmare to have in the house. They destroy food and infect surfaces and food with their feces, urine, and saliva. All three bodily fluids can carry Hantavirus which is a dangerous and possibly fatal respiratory ailment. If you have mice and you need to clean up a lot of feces then one direction you can go is with a vacuum cleaner. Most vacuum cleaners are not built for this kind of job, and an affordable vacuum purchased from a grocery store will quickly break down as it tries to suck up all the feces. Even a quality vacuum will have a lot of trouble even picking up the feces. The best option is a commercial-grade shop vac. These devices are expensive and very loud. Investing in one may be a good idea but the cost is very high compared to what you would expect for a vacuum cleaner.
Mouse droppings are surprisingly heavy and there will always be a lot of it. The feces also may not be on the floor, it could be in cupboards, under the dishwasher and fridge, and in all kinds of possible places. Trying to clean it all on your own is a waste of time. Call the professionals, we have to tools to not just clean the feces but to sterilize it and deodorize it. After we are done you would swear you never had mice at all.
While cleaning up mouse feces is a good start you will just be cleaning every day. The key to this situation is to get rid of the mice. Now that may sound impossible but it is not. It is something you could do on your own, but it would go faster with professionals getting involved. You can start by getting some weep vent filters, steel mesh, and a couple of cans of spray foam. Go around the house and seal up any entrance you can find. Once you have done this you will be mostly safe from new mice entering your home. Now you can start the extermination process.
The first step is to limit their movement. Make it so they have nowhere to hide. Remove boxes and un-needed items like old furniture or boxes or piles of newspaper. You can then find mouse holes and seal them. One strange thing you can do to dramatically limit their movement is to sprinkle human hair all over the floors of the affected area. Mice have no gag reflex and if a hair gets in their mouth they will choke to death right away. So sprinkle that hair everywhere and the mice will not be able to leave their nest. Once this is done place poison bait stations near the holes, this will be the only food they will have access to and will quickly kill them off.
When you have done all of this you should be free of mice, their feces and any other aspect of their presence. You should notice a change in the smell of the house, a new freshness and the air should be lighter without the mouse dander. Always remember if you are going to sweep up mouse feces to spray it with disinfectant first. If you have a good strong vacuum you can just vacuum it all up, there is no risk of hantavirus if you do that.