Welcome to Beesource!
I try to place my traps where I can get them at least elevated to slightly above head level. Usually that means attaching them to a tree.
Here is a study by Seeley on trapping swarms:
http://ecommons.cornell.edu/bitstream/1813/2653/2/Bait Hives for Honey Bees.pdf
(the link is in PDF format so you will need Adobe Reader to read it. Some devices/browsers have Reader functionality pre-installed)
I try to place my traps where I can get them at least elevated to slightly above head level. Usually that means attaching them to a tree.
Here is a study by Seeley on trapping swarms:
http://ecommons.cornell.edu/bitstream/1813/2653/2/Bait Hives for Honey Bees.pdf
(the link is in PDF format so you will need Adobe Reader to read it. Some devices/browsers have Reader functionality pre-installed)