Encyclopedias left in place, strangely, as attractive lures (6)
I believe the answer is:
decoys
'lures' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for decoys that I've seen before include "Lures" , "They're used to lure people into traps" , "Allures" , "Alluring things" .)