Bee welcome — swarm traps that work
The box to attract the bees — called bait hive or swarm trap — is basically any watertight wooden or plywood box with a volume of 40 to 70 liters (10 to 18 gallons) and a two-square-inch entrance towards the bottom of one wall.
Mid to end of April: swarm traps should be out. May and June: when most swarming occurs and swarms have the best survival rate as it's still early in the season. Trapsshould be checked weekly for drones and pollen going in which is when you know you have a swarm for sure.