Swarming and Catching a swarm with a swarm trap

The next few weeks will be the best time to catch a large swarm. Overwintered colonies are packed with bees, there is no widespread nectar flow, rainy weather is holding the bees in the hive. The feeling of overcrowding is going on now in many hives. Beekeepers are checking their hives weekly for swarm cells. Removing swarm cells before the cells are capped to prevent swarming.
 Finding a capped queen cell should make a beekeeper pause before the cells are removed. The hive usually swarms when the cell is capped. Not all the bees leave, only the field bees, The house bees can't fly yet.
 If a capped queen cell is to be removed, make sure a new queen can be obtained. If a queen is not available to purchase, the cell should stay so the queen can emerge to mate and take over as the new queen. By early June there are usually enough drones around and good temperatures for proper mating. 
Putting out a swarm trap can help catch a swarm, yours or another beekeepers.
A swarm trap is as simple as one deep box with a few frames in the box. Putting the trap in an elevated position can greatly increase the odds of a swarm moving in.
One way to elevate the swarm trap is to use an portable elevated deer stand.

Not this way

This is attractive to the bees. About 8 - 10 ft off the ground

A deep is needed for the box size for a swarm to want to move into. A five frame nuc box is too small for a swarm.
This is a video of a beekeeper that put his swarm trap on the top of an old truck. Watch the video and let him tell the story.