They can also be used as a substitute against a building that has low health and if the energy cost of the next Critter shot is cheaper than either Artillery or Barrage.
However, when using Smokey Warriors or Smokey Zookas, it is recommended to save the Critters to distract the defenses rather than use them to clear Mines, and use Artillery and Barrage in their place.
Be careful when attempting to distract Mortars, Rocket Launchers and Shock Launchers, as firing Critters directly at them will not work due to their blind spot. Instead, fire the Critters close enough to the defense as to attract the attention of the defense, but far enough as such that they will not enter the defenses' blind spot. To prevent them from entering their blind spots when they land, it is best to deploy them on another building outside the blind spot.
Do not worry about your Critters after you deploy them since they are not regular troops and are supposed to be destroyed to serve their job.
Critters can trigger Hot Pots leaving those open for a Shock Bomb and troops to destroy it. One can even throw a Shock Bomb on it to freeze it.
Critters can attack a Machine Gun without retaliation from the Machine Gun due to its blind spot. This also makes Machine Guns a good area to deploy Critters for distractions.
Do not leave your Economy and Support Buildings unprotected. Critters can be used to gain lots of free energy while remaining away from defenses.
There are no visual differences between levels. Critters always appear as small blue robots with two gun barrels that look like eyes at the front, and four legs. It also has a searchlight at the front.
Each upgrade increases the number of Critters deployed per shot by one.
Critters wander around your home base in the same way as the wildlife.
During an upgrade, they appear to walk around the building that is under construction/being upgraded unless it is an aquatic building.
Though they have a searchlight, they cannot fire through Smoke Screens.