Arduino 101 Analog input Pulses With no positive Input

I am semi-knowledgeable but also somewhat inexperienced with electronics, and i could not seem to think of a plausible reason my arduino would be doing this.

The symptoms: My arduino, when plugged into my computer or powered by a wall socket adapter, will read the input of it's analog pins in, what i assume is, a sine wave (for a lack of better words). I assume it is over 50-100 times a second. The highest and lowest values are more extreme when the arduino comes in contact with a solid surface. I fear this might be static damage.

You must connect something to an input if you want to read something sensible from that pin.
Arduino inputs are very high impedance, and therefore a ‘floating’ pin can easilly pick up things like 50hz mains power hum.