I found the Boxelder Bug (a North American species of true bug) in my semp beds last year.
They mainly feed on Acer seeds, they can sometimes pierce plant tissue while feeding. They are considered to be more of a nuisance than a threat to our gardens.
Boy was I relieved to learn that from Janet.
I had to use a magnifying lens to see what they looked like, all I could see were tiny red dots moving around.