That's because opposite poles attract and the "north" end of the compass needle, a north pole, is attracted to south poles.
(opposite poles; attract; ) (a north pole; is attracted; to south poles) Context(a north pole is attracted,List([81, 107))):(That; 's; because opposite poles attract and the "north" end of the compass needle)
a north pole is attracted,List([81, 107))
opposite poles a north pole That
attract is attracted 's
to south poles
because opposite poles attract and the "north" end of the compass needle