Often when you're running around, you'll encounter these "fields" of "dead" Guardians you can collect Ancient materials from. They look like this:
However, some of them are actually very much alive and will wake up if you get close and starting trying to laser you to death:
How can I figure out if a "dead" Guardian is still alive without "waking" it up?
If you’re wearing the Champion's Tunic, the guardian's health bar (if it’s alive) will show up. If I remember correctly, the range for this is bigger than the guardian's detection range.
Also, if the Master Sword's glowing, the guardian (or at least one in the vicinity if there are several) is alive.
A third way is to check with the camera. If you hover on an inactive guardian, it’ll show a bounding box and label the guardian as such; if it’s just a prop, it won’t show anything.
If you've upgraded your Stasis rune at the Hateno Ancient Tech Lab, activating Stasis will cause any "dead" Guardians that are actually alive to be highlighted in yellow.
