it still sounds like a carpet beetle. they're quite fond of either flying away from you or playing dead. their young (larvae) are usually found around paper products and linens (they chew through them and eat them), which is probably one reason you spotted the adults on the window shade. we've had books and towels that were in storage go in holes because of them but they usually aren't a brutal problem. if you find too many more you may want to consider setting off a bug bomb or fogger in your basement (or lower level of your home). if you do that you'll want to leave the house for the day (or even a couple days) and take your pets with you until the insecticides have settled and left the air. if they're not too numerous you could try just tossing the ones you find outside. they're nothing to fear, they do not bite, pinch or carry disease so picking them up with your fingers is ok. you may also wish to wash your linens, clothing items and washable stuffed animals and furs to remove any larvae or eggs. vacuuming on a regular basis is also helpful in controlling them. i recommend for the next two weeks vacuuming the whole house every day (even under beds, tables, behind desks, around heating/cooling registers, in closets, any place that may seem like a good hiding place for beetles).
