The big one is an assassin bug. The little ones are baby assassin bugs. Baby insects are called "nymphs".

They look more like leaffooted bugs to me.

Here is a link that might be useful:

Thanks for the IDs. I was hoping they were assassin bugs, but the leaffooted bug description fits better.

According to a webpage by Colorado State University, "Western conifer seed bugs [leaffooted bugs] are also sometimes mistaken for assassin bugs (Reduviidae family). They may similarly share an overall elongate body form and pointed head but there are many physical differences to separate them. Perhaps most obvious is the broad thickening of the hind legs on the wester conifer seed bug. Assassin bugs lack this and usually have a slightly thickened pair of front legs instead. The mouthparts of assassin bugs are more conspicuous, forming a pointed beak that projects from the front of the head. The mouthparts of the leaffooted bugs are tucked more closely to the body."

These bugs are hanging out on a seed pod and the adults have distinctly thickened hind legs. Also, now that I know what I'm looking for, the adults are clearly sucking on the thistle pod: