What type of animal is primarily referred to as an arthropod?

The term "arthropod" refers to a phylum of invertebrate animals characterized by their segmented bodies, jointed appendages, and exoskeletons made of chitin. Centipedes belong to the class Myriapoda within the phylum Arthropoda, which makes them a prime example of an arthropod.

Centipedes exhibit the foundational features of arthropods, including a segmented body that can have dozens of segments, each typically bearing one pair of legs. This segmentation, along with their jointed limbs and protective exoskeleton, clearly aligns with the defining characteristics of arthropods.

In contrast, the other options—house mouse, roof rat, and desert woodrat—are all mammals, belonging to the class Mammalia. Mammals have different anatomical features, including mammary glands for nursing their young, fur or hair, and a completely different skeletal structure compared to arthropods. Therefore, centipedes are appropriately identified as arthropods, while the other animals listed do not fit this classification.