>>3994106This is pedantic. Technically many insects are not "true bugs" (order Hemiptera) either. Colloquially, the term "bug" is often used to describe any small terrestrial arthropod, whether it be an insect, arachnid or even a land crustacean like woodlice. Pic related, an arachnid but I'm sure anyone who found it in an old book would call it a bug.
https://en.wiktionary.org/wiki/bug>An insect of the order Hemiptera (the “true bugs”)>(informal) Any insect, arachnid, or other terrestrial arthropod that is a pest.>(US) Any insect, arachnid, myriapod or entognath. 