The important thing to realise about things that go bump in the night is that they are generally the same things that go bump in the day. They often seem amplified because of the perceiver's lack of vision, which otherwise takes precedence over audio input, and the surroundings being rather quieter than usual.
Some of the most frequent bumps are caused by:
Domestic pets not only go bump, but whirr, crunch, scamper and make other assorted noises depending on what cage toys and/or food they have been given before the night in question. Another point aggravating this problem is that most domestic pets living inside are nocturnal anyway, so they have to make up for being boringly quiet during the day by bumping in the night.
Books and other shelf-living objects have a notorious tendency to slide, no matter how well balanced they are. They can fall over on the shelf, giving an alarming scrape followed by a spooky soft bump, or can fall off the shelves completely, giving a terrifying crescendo of sliding leading to a short but petrifying silence and then a positively heart attack-inducing clatter when the objects inevitably hit the floor.
Doors which make sounds that are caused by sloppy building work. Some fool of a builder makes a hole in your door frame into which a bolt fits a little too wide - and what are you left with? A door which rattles back and forth in the slightest air current. This is genuinely spooky as it sounds like phantom footsteps.
Thermal expansion and contraction are the ultimate culprits for things bumping in the night. They change constantly as the house cools down for the night, and naturally this makes it creak a little. However, when this occurs in floorboards, the creak tends to run from one end of a room to another, presumably because one board pushes another, so that you can think that some unseen being is traversing your room. Most of the time it's just the floorboards.
Burglars go bump in the night by their very nature, though not by their intention. They wouldn't go bump at all if they had appropriate technology to dampen out their footsteps. Many burglars are caught because of bumping in the night, which can be seen as a kind of burglar's scourge, in this capacity at least.
People needing the toilet always attempt to go quietly and, ironically, it is the people trying to go quietly who always make the most noise. Somebody creeping on tiptoes is much more likely to fall and make a horrifically loud bump, as many have learned to their social cost.
Plates and other crockery generally do not go bump by themselves, but need a person to be, for example, midnight snacking. If a plate is accidentally dropped, it will roll round and round for several seconds making a noise akin to a drum roll. Unless, that is, it is stopped first in which case it makes a loud crash as the base hits the floor; or it smashes, in which case the tinkles of fragments bouncing away add to what is already a formidable bump in the night.