A Missed-steak.
or
Stop bugging me!
or
Because he heard there would be a 50% chance of snow!
or
got salmonella.
or
Pooched eggs.
or
Hell, you need 250 just to lobby for the research grant.
or
Is that you mommy?
or
A Dogwood
or
They can't find the key, and they never know when to come in.
or
Because they don't want to give away their presence.
or