What's biting (someone)?

informal

something that you say in order to ask why someone is in a bad mood.

What's biting her? She hasn't said a word all morning.

• smell to high heaven
• smile from ear to ear
• smoke
• smoke and mirrors
• smoke-and-mirrors
• smoke out
• smoke out something
• smoke signals
• smoke someone out
• smoking gun
• smooth out
• smooth out something
• smooth over
• smooth over something
• smooth over the cracks
• smooth ruffled feathers
• smooth someone's ruffled feathers
• smooth the way for
• smooth the way for someone
• smooth the way for something
• snail mail
• snake in the grass
• snake oil
• snake-oil salesman
• snap head off