Based on your description of the bees, it sounds like you are dealing with carpenter bees. They are relatively large bees with a shiny black abdomen (rear part). If you can send us photos of the bees/damage, we would be happy to look and confirm their identity. 

Carpenter bees are not aggressive and they are valuable pollinators. One of our University of Maryland entomologists who specializes in pollinators recommended this website where carpenter bee biology and management is explained well: https://entomology.ca.uky.edu/ef611

If you don't want to have carpenter bees around the home, they can be managed by maintaining sound, finished wood surfaces. Painted surfaces are unattractive to nesting bees. Nail holes and cracks should be filled with caulk or putty before painting. Focus on repairing and painting structurally important wood. See our web page for tips on the prevention and management of carpenter bees.
https://extension.umd.edu/resource/carpenter-bees

The best times to treat wood with minimal kill would be late summer (after the summer emergence and before hibernation) or early spring (before nest building -- they are usually searching for nest sites in April-May). 

For preventing bird strikes on windows: The Cornell Lab of Ornithology is an excellent resource for research-based information on bird biology and behavior. They have a very good page that offers several things you can do to windows to help minimize bird collisions. https://www.allaboutbirds.org/news/why-birds-hit-windows-and-how-you-can-help-prevent-it/

Christa

Hello!

Sorry I missed you. I'll be out of the office today and will return
June 8th, 2021.


I will do my best to get back to you as soon as possible.


Take care,
Agnes



-- 



*Agnes Kedmenecz **Woodland Stewardship Educator*

University of Maryland Extension
Wye Research and Education Center
PO Box 169 | Queenstown, MD 21658-0169
tel 410.827.8056 x125 | mobile 410.310.8445
http://extension.umd.edu

[image: Image result for find us on facebook]
<https:>
*@MDDEMasterLogger*</https:>