In principle, nothing should be put under the bed. In the theory of geomantic omen, if you want to hide wind and gather gas at home, you must keep the space clear and free from sundries. Putting things under the bed directly affects the gas field at home, which is not conducive to hiding wind and gathering gas. If the things below are wet for a while, they will turn yellow and have a taste, which will further destroy the gas field at home. Moreover, the space under the bed is already small, so there won't be enough space to put some larger items.
So, please try not to pile things under the bed.