Passive single coil pickups certainly do pick up hum, but shielding cavities can be pretty effective. As the Toneriders should have one pickup wired reverse wound/reverse polarity to the other, with both pickups on at matched volumes, the pickups become humbucking, so will generate a lot less hum than if just one pickup is in use.

But the pickups can only pick up hum that’s around, they don’t generate it themselves. So if you have an electrically quiet environment, there’s little or no noise to pick up. But don’t assume they will always be quite so quiet when playing in a different location.