MOSQUITO is a simple app to demonstrate the use of overlays in DirectDraw.
To run the app you must have a display adapter and driver which support
overlays.

On a machine with overlay support, the app creates a big flapping mosquito
which flys around the screen.   If you're card doesn't support "Source Color
Keying" of overlays, you'll see an ugly black rectangular background around
the mosquito.

Some cards have better overlay support in certain resolutions that others.
If you know your card has overlay support through DirectDraw, but Mosquito
is having problems creating or displaying the overlay, try running the
application in a lower screen resolution and/or color depth.