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."
[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. Thus, the process of investigating the original-computer-bug bug fixed it in an entirely unexpected way, by making the myth true! —- ESR]
[1992 update: the plot thickens! A usually reliable source reports having seen The Bug at the Smithsonian in 1978. I am unable to reconcile the conflicting histories I have been offered, and merely report this fact here. —- 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.) previous releases of itself. "MS-DOS 2.0 used \ as a path separator to be bug-compatible with some cretin's choice of / as an option character in 1.0."
:bug-for-bug compatible: n. Same as {bug-compatible}, with the additional implication that much tedious effort went into ensuring that each (known) bug was replicated.
:buglix: /buhg'liks/ n. Pejorative term referring to DEC's ULTRIX operating system in its earlier *severely* buggy versions. Still used to describe ULTRIX, but without venom. Compare {AIDX}, {HP-SUX}, {Nominal Semidestructor}, {Telerat}, {sun-stools}.
:bulletproof: adj. Used of an algorithm or implementation considered extremely {robust}; lossage-resistant; capable of correctly recovering from any imaginable exception condition. This is a rare and valued quality. Syn. {armor-plated}.