Dot maps can be very misleading if not created properly. The map below was created in a version of the analysis software Atlas Pro which places dots randomly within the enumeration units (in this case, countries of North America). Note that this method results in the implication that there are at least as many alligators in the midwest and the desert southwest as there are in Florida.
The map below was transferred to a drawing program (FreeHand) and the dots were moved to more logical positions. Dot maps are difficult and cumbersome to create appropriately; unless a good deal is known about the processes underlying the phenomenon (like the fact that alligators prefer swamps to deserts), dot maps should be avoided or used with caution and awareness.
Note: there are numerous other design problems with these maps. The color of the dots, for example, is the same (black) as the color of the country boundaries; the map would be much easier to read had the dots been red.