Circuitmess Wacky Robot Mr. Bee Instructions Manual page 31

Pay attention to the polarity of the LEDs as you connect them.
Look for the rounded part (that's the plus side) and the cut-
off part (that's the minus side) marked on the LED.
If you flip Mr. Bee around, you'll notice the + and - signs next
to each connector. Those represent the polarity.
+ & - signs that
mark the polarity
For some extra fun, you can connect Mr. Bee to the Bit gaming console
(Bit sold separately), and the LED will light up to create a cool effect.
If, by any chance, the LED doesn't light up, no worries
– just remove it and place it on the opposite side.
+
Rounded
part
+
-
Rounded
Cut-off
part
part
-
Cut-off
part