// fecundity in code
Weirdly enough, Fecundity is a property of source code entities (loosely defined here as any recognizable pattern in source code)— source code entities multiply, and thus create copies of themselves.
Fecundity levels are different for different types of code entities. Many entities multiply readily by being copypasta, like Stack Overflow snippets and boilerplate code. Some entities are slower to get around and must be helped along, such as new language API releases (think Java 8 streams, or ES6 arrow functions. How long did those take to get fully adopted in your project, if ever?). A few (the best) types of code entities only multiply through thoughtful human endeavour, such as sound architectures and useful best practices.
Bugs are the most fertile type of code entity. Bugs will appear spontaneously, in the presence or the absence of effort. Indeed, to a point, the less effort is expended, the more bugs will breed.
Bugs of any ilk will give birth to bugs of any other ilk. Furthermore, bugs like to mate and produce kid bugs that share none of the attributes of the parent bugs.
Squash them first! Squash the bugs before you do anything else, because if you don’t, like barnacles on a ship they’ll bring your project to a grinding halt.