Bumble bees are great pollinators for a number of garden crops and flowers. They are docile, fly early in the morning, later at night than honey bees and when the weather is poor (colder and rainy). Early in the spring the overwintering females search out a nest and begin foraging and egg laying, once their are enough drones the queen will stay in the nest and the drones will take over the food collection for the colony. This instructable demonstrates how to build an attractive (to a bumble bee) nest to attract local bumble bees and improve your yard/garden pollination.
-8 inch ceramic pot (larger like 10in will work but not any smaller)
-8 inch ceramic coaster
-screen material (about 5x5in piece)
-chicken wire (about 12x12in piece)
-regular garden hose (1.5 feet)
-glue (I used liquid nails, but gorilla glue or something else would be fine too)
-Drill with small bit (7/64 was what I used), you could also hammer a nail through the hose throughout.
* I searched prior to making the instructable and didn't find any that were similar, but today I just saw janw'sbumble bee instructable (https://www.instructables.com/id/Build-a-Nest-Box-f...) and wanted to make sure to give a shout out. I have had great success with the clay pot design but depending on what you've got on hand this may be good to try.
Step 1: Keeping Pests Out of the Vent
The nest needs a vent hole to allow fresh air in. The clay pot controls moisture well and is equip with a vent hole. The vent needs covered with screening to keep other pests (like ants) out of the nest, granted the main entrance is at the ground level an invites other pests to enter but the bees tend to be more efficient at defending a single entrance.
Step 2: The Entrance
Next I prepare the entrance (piece of regular garden hose ~30 cm long) by drilling small holes through it at 3cm spacing. This allows liquid to drain out and keep the "tunnel" clear of water.
Step 3: Preparing the Nesting Cavity
Bumble bees like to nest in material similar to a used mouse nest. I used craft stuffing which I pulled apart to loosen it up. I then lightly stuffed it into a chicken wire cradle to support it. The nest is then place into the bottom of the pot, pressed in so that it stays in the bottom once the pot is flipped upside down.
Step 4: Installing the Nest
Next place the hose so that one end is barely into the chicken wire and the other end loops out of the pot. Then dig a circle and tunnel away about 5cm deep in the desire part of the garden/flower bed. Place the pot upside down into the hole with the outside section of hose in the tunnel leading away. Push the dirt back up against the edge of the pot and over the hose to bury all but a few cm at the end (because I was using bark and it wasn't staying down placed a rock over the end part). Lastly place the ceramic coaster piece over the top of the pot to keep water out. All done now you have a nesting box for bumble bees, if you built it in the early spring before the trees leafed out than you should only have to wait a couple months before you see bees enter and leave the entrance hose!