How long does it take for a partially-finished cup of coffee with cream to grow mold? (I sometimes did this at work when I didn't take my cup back to the staff kitchen.)
Which gets moldy faster, white bread or rye bread? (This is one of my husband's favorite experiments.)
How long can a fly live inside a house?
How many hours on the average does the ordinary adult housecat sleep in a 24-hour period?