A. Leg count
B. Web abilities
C. Density of skin
D. Intelligence
Details About Why aren’t spiders’ insects:
Though there are more than 900,000 insect species on the planet, none of the 51,673 species of spiders are found there. The rationale is that while some insects, like ants, are categorized as having six legs, other organisms such as spiders, ticks, millipedes, and many more are not considered insects. They don’t fly or have antennae, but this is the primary explanation.