Density control in a wireless sensor network refers to the process of deciding which node is eligible to sleep (enter power-saving mode) after random deployment to conserve energy while retaining network coverage. Most existing approaches toward this problem require sensor's location information, which may be impractical considering costly locating overheads. This paper proposes a new density control protocol that needs sensor-to-sensor distance but no location information. It attempts to approach an optimal sensor selection pattern that demands the least number of working (awake) sensors. Simulation results indicate that the proposed protocol is comparable to its location-based counterpart in terms of coverage quality and the reduction of working sensors.