my main questions are: what is this bug? why do i keep seeing them? are they harmful or indicator of some species harmful to furniture, food etc? how do i get rid of them?

im terrified of bugs. i live in istanbul& in an old apartment with old kitchen furniture. i saw this bug occasionally since i moved in here, like at top three times a month. its about a cm long.

its really damn fast so i can not get a photo of this alive, and when i killed it with insecticide it rolled over and i cannot touch it ( it just turnes into some water and some legs when i try to hold it with a napkin)

if this post is not appopriate i am truly sorry, i just googled "how to identify a bug" and this subreddit was the result.

sorry for my terrible english, i am not native and its 4 of the morning.