If you add a gagillion boids, the page may get laggy or stop playing altogether. I'm pretty sure this is a Tone.js limitation (well, a "my current usage of Tone.js" limitation, specifically!), and if you have an idea of how to work around it, please let me know! In the meantime, simply refresh your screen to start fresh (or un-toggle "wrap world" to let some of your flocks fly away).