A cockroach may only appear to have four legs from the outside, but that doesn’t mean it doesn’t have any legs. Roaches sometimes have legs so small they appear to have four legs beneath their body, giving the appearance that they have four legs.
In addition, not all cockroaches have six legs. Scavenging and exploring fresh environments enable roaches to survive despite losing limbs or two. Perhaps you’ll spot one with four or even five legs, hobbling along without seeming to care.
Even cockroaches can regenerate lost legs thanks to an amazing gene in their genome! When the five-legged cockroach had been left alone long enough, it would eventually revert to its original six-legged state.