Teletubies blowing up London?

Reacently I had a dream about the teletubbies turning up at my doorstep they were like adult size and held these lazer guns and they used to shoot people and kill them, people were scared and hid in ther houses and if a teletubie knowcked on there door, they have to be quiet or else they'll die! lol and theres one time they blow up have of london, including the london bridge, but why do i have these weird dreams about them?