This paper analyzes the impact of blackhole attacks on single hop and multihop Low Energy Adaptive Clustering Hierarchy (LEACH) protocols in wireless sensor networks (WSN). Simulation results demonstrate that the blackhole attack significantly reduces data transmission and affects the energy consumption and longevity of nodes, with multihop LEACH being more adversely affected than single hop LEACH. Ultimately, the findings suggest that while single hop LEACH maintains higher data transmission and energy metrics, it is still vulnerable to such attacks.