Based on your photos, these irregular shaped holes may have been created by a woodpecker. Wood boring insects tend to keep their burrowing under the bark until they emerge as adults (typically beetles), creating smooth edged, regular shaped emergence holes.

It is difficult to tell for sure from the photos, but what you could be seeing oozing from the holes is cedar sap, that sometimes dry and form irregular shapes and bumps that resemble insect larvae. But we cannot rule out for sure that there are not wood boring insects within the tree.

Some woodpeckers create these holes with the purpose of extracting sap to attract external flying insects for them to eat.

If you have concerns over the health of the tree (any signs of tree decline such as branch or canopy dieback), we recommend contacting a professional certified arborist. Certified arborists can be found through this list by the MD Department of Natural Resources: https://dnr.maryland.gov/forests/Pages/programapps/newtreeexpert.aspx or through the International Society of Arboriculture website: https://www.treesaregood.org/findanarborist/arboristsearch. 

For more information on woodpeckers please see our extension page: https://extension.umd.edu/resource/woodpecker-and-sapsucker-damage-trees/.