Tapping

I was in my room talking to my friend on MSN(Instant Messenger). We were playing voice clips. And suddenly something taps really loudly in the next room. I'm upstairs alone. And when I check the room the doors shut. I call out to my parents. They are both down stairs. And my cat and dogs were two.

I was laughing loud so maybe I disturbed something? It was quite loud. I was also tapping before that, So It was tapping back?