Small black slow-moving insect showing up in the home
Based on the hard-looking outer "shell" and elongated nose, this is certainly a type of beetle called a  weevil.

Given the size of the weevil, the time of year and the location of your home (second floor in a large city), I would guess this is certainly some species of nuisance/pest weevil. 

Candidates include:

Wheat weevil (Sitophilus granarius)




Range: Worldwide
Food: wheat, oats, rye, barley, rice and corn
Appearance: 3–5 mm long with elongated snouts; reddish-brown 
Life History: 36-254 eggs in 5-20 weeks


Rice weevil (Sitophilus oryzae)




Range: worldwide
Food: wheat, rice, and corn
Appearance: 2-3 mm, long nose, brown/black in color with 4 orange/red spots
Life History: 300 - 400 eggs per month [source]
Note: can fly


Maize weevil (Sitophilus zeamais)




Range: cosmopolitan in warmer climes [source]
Food:  corn (maize), wheat, rice, sorghum, oats, barley, rye, buckwheat, peas, cottonseed, other types of stored, processed cereal products (e.g.,  pasta, cassava, other coarse milled grains), and even has been known to attack fruit while in storage (e.g., apples)
Appearance:  2.5 - 4 mm, brown with four reddish-brown spots on elytra, long/thin snout, and elbowed antennae


See this Wikipedia page for a comparison of the rice vs. maize weevils

Life history: 300 - 400 eggs per 36 days


If you've been seeing multiple of them, that likely means they are breeding in some container of grain (wheat, rice or corn perhaps) you have in your home and could be well on their way to an infestation if your grain source is large enough. I recommend you check all sources of dried foods in your home to see if you hear/see weevils in it or coming out of the container.

Given the relatively large number of eggs each female can lay and given the month long generation time, this is an infestation you'd like to stop quickly. 

 Note: all info is from the linked/cited Wikipedia pages unless otherwise cited.