In any case, in jargon the word almost never refers to insects.
Here is a plausible conversation that never actually happened:

"There is a bug in this ant farm!"

"What do you mean? I don't see any ants in it."

"That's the bug."

A careful discussion of the etymological issues can be found in a
paper by Fred R. Shapiro, 1987, "Entomology of the Computer Bug:
History and Folklore", American Speech 62(4):376-378.

[There has been a widespread myth that the original bug was moved
to the Smithsonian, and an earlier version of this entry so
asserted. A correspondent who thought to check discovered that the
bug was not there. While investigating this in late 1990, your
editor discovered that the NSWC still had the bug, but had
unsuccessfully tried to get the Smithsonian to accept it -- and
that the present curator of their History of American Technology
Museum didn't know this and agreed that it would make a worthwhile
exhibit. It was moved to the Smithsonian in mid-1991, but due to
space and money constraints has not yet been exhibited. Thus, the
process of investigating the original-computer-bug bug fixed it in
an entirely unexpected way, by making the myth true! --ESR]

:bug-compatible: /adj./ Said of a design or revision that has
been badly compromised by a requirement to be compatible with
{fossil}s or {misfeature}s in other programs or (esp.)