Pretty simple. Take an empty plastic jug (the example shown of course is a milk jug), but any jug will work. Milk jugs seem to work the best. I f you live in an area where bees are especially bad, one could certainly make one out of a 5 gallon bucket with a lid. But if you have bees so bad you need a giant bee trap....MOVE!! Get the hell out of there!!! LOL
But seriously. Just cut a couple holes in the side of the jug as shown. I think my example only shows 2 holes, but 3 are better. You don't really want to do 4, you want a little rigitity left. Poke a small hole in the cap and feed in a small wire. Tie a washer or something to keep the end from sliding through.
Fill the bottom of your trap with regular old water and give it a couple shots of dishwashing liquid.
Tie some sort of raw meat to the end of your wire and let it hang just above the soapy water.
The bees will buzz around inside and eventually come in contact with the water, they only have to touch it slightly and they are done.
In all the years I have used one of these I have noticed very few bees come out once they enter.
The key is to keep the bait as close to the water as possible and keep the water level up to the bait. The stinkier the better!!!
(authors note: I once had only one or two bees fucking around, I made one of these bee traps, and in less than 15 minutes the entire surface of the water was covered. I didn't see that many bees when I set it out, but they sure came. Perhaps it was to help their distressed bees. Don't know, don't care. Build it and they will come.)