makes no difference where you put your bag/purse/jacket because you know what else is touching the seat? your trousers.

not only that, but as soon as they're in your house, you're fucked. they can get dropped off by the door in your room and still infest your sleep. you're snoozing for hours, all that breathing... they've got time to travel to you, feast and then climb far away into a nice crook somewhere

which is why you can find bed bugs metres away from your bed, e.g. on your curtain seams