The tendency of a household to became increasingly disorganized, untidy, and unmanagable.
Rather than compress into small spaces, items tend to redistribute to evenly fill all available space (the Stuffed Animal Effect). Rather than organize into separate, homogeneous, classifiable and finite collections, items tend to mix into heterogenous open sets (the Junk Drawer Effect). Even if they are not used, without intervention items and surfaces inevitably get dirtier and not cleaner (the Crunchy Towel Effect). Partially enclosed items left unobserved for an extended period will, when retrieved for use, contain one or more dead bugs (the Cuisinart Effect). Attempts to organize specific areas will always result in some other area becoming less organized (the Spare Linen Effect).
The tendency of the household toward randomness is a feedback cycle. Disorganization leads to perceived attrition which leads to aquisition of additional items, which in turn increase the Domestic Entropy of the household (the Nine Rolls of Sticky Tape Effect).
I'm in a constant battle against domestic entropy; if I miss my chores one night before bedtime, by the next morning the house is so messy it would be easier to burn it down and build anew than to get it clean again.