Besides which, we humans derive our base 10 system from counting on our fingers, not from our four limbs. Note that insects have dual tarsal claws in this image: bugguide.net/images/raw/2ZZLWZMLWZILWZ2HBHHL1HHLVHIHCHLLCHHL1HMHTHLLAHRLEZ8LLREHYHMLLRMLWZLLAH8HPZLLTH.jpg insect leg And, since most insects use their forelimbs as arms, effectively, they have four fingers total. Thus their numbering system would be base 4. www.cksinfo.com/clipart/animals/insects/prayingmantis/preying-mantis-BW.png praying mantis Gotta love this digression.