Here's how to build a bee house for your pollinator friends:

• House walls: an empty milk carton (waterproof) with the spout cut off - leave the bottom intact - or a box about that size made of wood scraps (not cedar).

• Paint a wooden house a bright colour with exterior zero- or low-VOC (volatile organic compounds) paint. At first, the bees will fly around taking mental "snapshots" of their potential new home, but they'll soon learn to make a bee-line to their new abode. If you plan to make more than one bee house, be sure they're different colours.

• Fill the box with layered stacks of brown paper nest tubes, which you can buy at a garden store. Cut the tubes to six inches (15.75 cm) long, closing the end with tape or a staple, or fold them in half. Commercial nest tubes are 5/16 of an inch (.79 cm) in diameter, the exact size of an HB pencil. Make your own by rolling a piece of brown paper around a pencil, then pinch off the end and seal it with tape.

• Hang the house somewhere out of the rain, facing south or east, at eye level, once the temperature outside has warmed to 12-14º C (54-57º F).

• Dig down below your garden soil adjacent to your bee house until you expose the clay layer, or keep a bowl of moist clay near your bee house for the masons to use as construction material.

• It may take a full season for the bees to find your house. If you don't have any luck attracting locals, you can also purchase mason bees from a garden store or local bee keeper.