Abstract: A blood lancet is disclosed that has a base; a needle mounted to the base; a cap that slides relative to the base, and a locking member located inside between the base and cap. In use, the base and cap are initially at an expanded position and the needle is retracted below a hole in the cap. When the user is ready to draw a blood sample, the user positions a finger on the cap and squeezes the base and cap together. The locking member initially resists the movement of the cap until sufficient force is applied to snap the locking member into the cap, which permits the cap to quickly retract to expose the needle and prick the user's finger. This movement also spreads apart two cantilever springs that bias the cap back toward the initial expanded position. When the user stops squeezing the base and cap together, the springs push the cap and the locking member, which is now engaging the cap, to the expanded position.