Pig primarily investigates with nose, uprooting new problems (7)
I believe the answer is:
puzzles
'problems' is the definition.
(I know this)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for puzzles that I've seen before include "Crosswords?" , "such as Enigma and Maze" , "Games that test mental skills" , "Perplexes" .)