Lingaku- see 一粒老鼠屎坏了一锅粥【yī lì lǎo shǔ shǐ huài le yī guō zhōu】
Generated: This phrase suggests that even a small amount of negativity or a minor mistake can affect a more significant situation or outcome.
A tiny bit of rat droppings can ruin a pot of porridge, meaning small issues can affect the whole.