Black beetle/ants in my room ?X?

ok so i was just in myu room cleaning up and a little black bug about 1 cm long looked like a ant/beetle thing was crawling on my carpet i killed the first one then saw another my dad got it i cant see anymore atm im gunna hoover up in 5 mins but i dont know what they are or where they came from althought i did camp out with some mates last night and my camping stuff was on my bedroom florr help eeek ??x