Unmanned drones are shrinking -- yet their presence in the U.S. military arsenal is growing.

AeroVironment’s Wasp AE represents the latest evolution in unmanned aerial vehicles (UAVs). The Wasp has been used by the U.S. military for small unit work ranging from reconnaissance and surveillance to tactical intelligence. Hand-launchable at just 2.8 pounds and 16 inches from wingtip to tip, the new model flies 20 percent longer than its predecessor.

The company’s work more than a decade ago on the Black Widow program resulted in a 6-ounce, 6-inch wide micro vehicle that laid the groundwork for today’s micro drones.

And after a year of evaluation and user testing, the U.S. Air Force gave it the stamp of approval, announcing May 22 that the Wasp AE will be included in its Battlefield Air Targeting Micro Air Vehicle (BATMAV) program and placing an order for nearly $2.5 million.

On May 16, the U.S. Army ordered more than $5 million worth of the companion Switchblade UAV, adding to a previous order for $4.9 million.

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Able to land on either land or water, the Wasp is fit for both ground warfare and maritime operations. It can relay encrypted video, and voice, text and data, and a miniaturized Mantis i22 AE sensor package lets it capture both color and infrared imagery.

The kicker is that the Wasp is interoperable with other unmanned systems -- meaning it is capable of working as a team with other machines to attack the enemy.

While a digital data link lets it work with a variety of other drones -- with names like the Puma, Raven and Shrike -- the coolest tag team is clearly its partnership with the Switchblade.

In this pairing, Wasp provides the eyes in the sky as Switchblade, also developed by AeroVironment, provides the firepower.

Known popularly as “the kamikaze drone,” the Switchblade works sort of like a grenade and can be guided to a target and set to explode upon impact.

With its micro size and quiet electric propulsion, the Switchblade is difficult for an enemy to track and can arrive on target without detection.

Like the Wasp AE, Switchblade can be either autonomous or remotely controlled by an operator. This lethal platform can recognize objects and provide real-time GPS coordinates and video.

At 5.5 pounds, it fits in a backpack and lets a soldier unleash munitions against even out of sight targets within minutes.

The four-winged UAV is housed in a small tube that is readily pulled out of a backpack and launched from a vehicle, ship or off the ground with a remote controller. When Switchblade has been released, its wings spring open, its propeller starts spinning, and it can move at up to 85 knots (nearly 100 miles per hour).

Switchblade can lock on to a target, and can follow even if it moves -- switching off and re-engaging later if need be -- meaning minimized collateral damage.

Picture a small unit that comes across insurgents hiding IEDs (improvised explosive devices) and planning to attack U.S. forces. With a Switchblade that unit can immediately strike, remaining safely out of harm’s way.

Teams often have to compete with other units for UAV support -- this could help reduce the wait for such key airstrike support, and prevent the enemy from slipping away.

Switchblade is typically deployed by Special Forces units, but brigades like Infantry Brigade Combat Team, 1st Infantry Division will also begin fielding it this year.

The Air Force has also been using Switchblade -- and now the Marine Corps is moving toward procurement as well, to enable its small units to strike more quickly.

Two little machines that fit in a backpack -- but the potential is great.

Ballet dancer turned defense specialist Allison Barrie has traveled around the world covering the military, terrorism, weapons advancements and life on the front line. You can reach her at wargames@foxnews.com or follow her on Twitter @Allison_Barrie