It's necessary to use a reduced deck of 32 cards (a full deck is 52 cards) so the Snake finishes without extra cards at the end.
To make a reduced deck, remove these cards:
Remove two of each:
- notes - sixteenth, eighth, quarter, half, whole
- rests - sixteenth, eighth, quarter, half, whole
Remove four of each:
- dotted notes - eighth, quarter, half

It's fun for students to do the sorting.

The video shows students sorting for the first time.
Rhythm Playing Cards - Reduced Deck from Music Mind Games on Vimeo.