The Lickers are far tougher than in previous Resident Evil games. However, they have a weakness-- a "heart" hanging down from their chest. The best way to target this is to use a rifle (for example, the PSG-1). Try to aim at the darker red bulge. If you cannot get a clear shot at it, score a head shot to make them recoil, making the chest more vulnerable and easier to shoot. With the PSG-1, this will allow for a two shot kill, or even a one shot kill if you can hit the heart with the first shot. Hand grenades also work very well. They will completely disappear when hit with a grenade. This is very useful in Chapter 5-3 when you have to face a large number of them.