Movers usually don't expect a tip but is appreciated when given.

 Basically, if it's a half-day (4 hours) move, $10 per person is considered appropriate. If it's a full-day move (8 hours), then $20 is the consensus. If you have a lot of heavy furniture, narrow or winding stairs, a steep lot, etc., you should consider adding to the amount. If the crew works 12 hours to get your belongings packed, figure $40 as fair.

http://www.moving.com/articles/tipping-movers.asp?