Cockroaches are morons in the morning and geniuses in the evening
 

A new study has found that cockroaches are morons in the morning and geniuses in the evening in terms of their learning capacity. Previous studies suggest that the learning capacity of both people and rats are also affected by their internal biological clocks. But the effect is far more dramatic in cockroaches and it is the first time it has been found in insects. And, no, the researchers didn't try giving their cockroaches a sip of coffee to see if it revived them!

http://www.vanderbilt.edu/exploratio...cockroach.html