Mason Bee Observer


Our Mason Bee Observer lets you peek into and watch mason bees build their nests.

The clear window also allows you to watch mason bee larvae grow and spin cocoons.

Installation Instructions

  • If female bees are already nesting in your bee house, install the Bee Observer in the evening. 
  • Place the Bee Observer in your bee house under your nesting materials (BeeTubesTM with Inserts, Natural Reeds, Wood Trays), with the open end of nesting cavities facing out. To protect the bee observer from warping due to rain that may have collected at the bottom of your bee house, elevate the observer with a few thin sticks, dowels, or even pencils. 
  • The Bee Observer is designed to be used within a bee house that has a 2-3” roof overhang to protect against rain.


The Bee Observer measures 5 1/2" Wide by 6 1/4" Deep by 1 1/4" High. These are exact, so if adding to a non-Crown Bees house, be sure to allow a little extra room. 

 Observation During Nesting

  • To lessen disturbance of the nesting bees, observe one to two times a day—preferably in the evening.
  • After observation, gently ensure the wood nesting tray is pushed to the back of the Bee Observer drawer. 

Observation During Larval Development

  • When female mason bees are done nesting (usually in late spring), remove both the Bee Observer drawer and Wood Nesting Tray from your bee house. Store in a safe area that mimics outdoor temps (necessary for development) and check often to watch the bees grow and spin their cocoons!
  • Give the bee larvae their naturally dark environment by keeping the wood tray inside of the drawer after observation.

Fall Mason Bee Cocoon Harvest October to December

  • Remove the four screws from the acrylic lid.
  • Remove the bee cocoons with a Cocoon Comb.
  • Clean the nesting tray with a dry, stiff brush or old toothbrush.
  • Use CleanBee to treat any visible signs of chalkbrood or mold. There is no need to treat the entire surface.
  • Soak the acrylic window in water for a few minutes to avoid scratching. Rinse and wipe with a soft cloth if necessary. 
  • Allow all surfaces to dry completely.
  • Reattach the acrylic window, tightening the screws until just snug. If you overtighten the screws, the acrylic cover may break.
  • The Bee Observer drawer was treated with Daly's Ship'n'Shore, a non-toxic waterproofing, drying agent with linseed oil.

Mason Bee Observer in Action


Don't forget to sign up for BeeMail and get monthly beekeeping tips and reminders for how to raise your mason and leafcutter bees!