Complex sentence: Soon after the boy went into the cave, a three-legged rabbit hobbled across the way, the other lads followed it spontaneously in order to catch it, but the farther they chased the faster the rabbit ran.
Split into simpler sentences: Soon after the boy was in the cave, a three-legged rabbit hobbled across the way. Spontaneously the other lads followed it in order to catch it, but the farther they chased after the faster the rabbit ran.