Where they nest
A swarm needs a dry cavity with a small entrance it can defend. On a Yuma property there are more of those than anyone expects, and the worst of them sit exactly where people walk.
Water meter and irrigation valve boxes
A meter box is dry, shaded, thermally stable and has exactly one small opening. From a bee's point of view it is close to perfect. From ours it is the worst possible location, because nobody expects a colony at ground level beside the pavement, and the lid gets lifted by meter readers, gardeners and homeowners without a second thought.
Lift box lids with care from April onwards. Stand to the side, lift slowly, and look before reaching.
Wall voids and roof tiles
Bees get in through a weep hole, a gap under a tile, a vent screen that has torn, or the oversize hole where an air-conditioner line set enters. Inside is a stud bay or the space above a ceiling — a cavity as large as they will ever need.
The tell is steady two-way traffic at one specific point on an exterior wall, strongest in mid-morning. Stand back and watch for a minute: foragers leaving and returning in a consistent line means a colony, not a passing swarm.
These are the expensive ones, because getting the comb out means opening the wall or lifting tiles. What that involves.
The rest of the list
Sheds and outbuildings
Especially ones nobody has opened since spring.
Barbecues and equipment
Closed since last season, with one small vent.
Saguaro and palm cavities
Old woodpecker holes in saguaro; the dead skirt of an untrimmed palm.
Block walls
Hollow block with a broken cap or open cells at the top.
Disused vehicles
Under a bonnet, inside a bumper, in a boat left on a trailer.
Pool equipment
Pump housings and the space behind the filter.
The empty-house problem
A large share of the Foothills stands closed from April to October — exactly the season when swarms move. A house nobody visits for six months can grow a full colony in a wall with nobody to notice the traffic at the weep hole.
Owners come back in November to a colony that has had half a year to build. If you leave for the summer, have someone walk the property monthly and look at the walls and boxes. It is five minutes, and it is the difference between a routine removal and opening a ceiling.
Before you start yard work
Every spring in Arizona someone is hospitalised for starting a mower near a colony nobody knew about. Two minutes of looking prevents it:
- Walk the perimeter and watch for steady traffic at one spot on a wall.
- Check meter and valve box lids from the side before lifting.
- Look under the eaves and along the roof line.
- Open sheds and barbecues slowly, from behind the door.
- If you see traffic, stop. Do not start an engine near it.