The words below share an unusual quality, especially #'s 1 and 2, which are doubly unusual. Can you determine what makes these words distinctive?

1. PACK
2. LOOK
3. HAND
4. SUGAR
5. CHOCOLATE

HINT:
It has to do with words which can precede and follow the clue words.

Answers:

Each word can be both preceded and followed by the same word:

1. PACK RAT - RATPACK
    ICE PACK - PACK ICE
2. OUTLOOK - LOOK OUT
     OVERLOOK - LOOK OVER
3. OVER HAND - HAND OVER
4. MAPLE SUGAR - SUGAR MAPLE
5. MILK CHOCOLATE - CHOCOLATE MILK