Why is my B making these sounds?

I have recently bought an Ibanez electric b and a small Peavey practice amp, and, when turned on, the amp emits crackling, humming noises. This isn't that strange, except for the fact that they get louder and softer based on the direction i point the neck of the B and, even stranger, when i take it outside of my room, the noises almost (but not quite) stop. My house is very old 100 years+, and when practicing at a friend's, i can not hear the noise, but this may be due to other instruments playing.