hahah thomas, my way of dealing wif 'territorial animals' is to become 1 myself.
See, im not a plant lover, but sometimes planting pots of plants along the corridor has its advantage.
Im sure we see ppl dumping their used cabinets outside corridor or placing some bicycles or shoe racks just to demarcate the territory.
As for noise (Lingz), it's getting common nowadays for affluent hdb dwellers for owning a piano for their kids. Welcome to the congregation of little mozarts, not forgetting the level of noise/sound/music or watever u call it. lol