My first thought is you could have termites; they can be found in the best homes cluttered or not cluttered. They are usually whitish or clear some with wings are darker. They love to live in dark places.

Another idea is silverfish, which also love dark, damp and warm places in a house. They love wallpaper and book bindings. With air conditioning and dehumidifiers you can decrease their population in your home. Remove their food source such as boxes of books and old clothes can reduce your problem. These items do not have to be discarded but need to be cleaned; there are suggested chemicals you can personally use.

Before buying supplies and outfits I would suggest a large clear plastic bag. Pick up one of your binders carefully from the basement, place it in the bag and bring this to an exterminator or science lab of some sort where the pest can be identified. You may find it easier and safer to use a professional exterminator. Once you know what kind of bug it is you can find a specialist.

Personally I would not want to be in the basement until you know what kind of pests you have. If you disturb their place, they may just find a new home in your basement, or they may decide to find a dark place upstairs. If you throw everything away in your basement, you most likely will still have the pests. However by getting rid of the clutter you will make it easier for the exterminator.