First fireflies of the year, and something smells dead

First yesterday morning in the back yard one flew drunkenly into a flowerpot.  Then last evening, a couple sparking under the shad bush out front.  Meanwhile, there's the smell of something dead in the front of the house.  First, a couple of days ago, from behind the radiator or under the floorboards as you walked into the house.  Now, this morning, closer to the wall by the entry way, between the door and the living room.  I can smell it while sitting in the big chair we've promised to the silver fox.