Holes in stair risers?

[Mitchell Chiger]

Hello All,
Has anyone ever seen this type of holes in the risers in stairs. These are in a set of stairs rising to an attic. As always your input is appreciated.

[gary carroll]

Hello All,
Has anyone ever seen this type of holes in the risers in stairs. These are in a set of stairs rising to an attic. As always your input is appreciated.

I don't see a photo attached.

[H.G. Watson, Sr.]

I don't see a photo attached.
because its here:

http://www.inspectionnews.net/home_inspection/structural-components-home-inspection-commercial-inspection/34045-holes-stair-risers-here-picture.html