The ability to make undetected, stealth movements could mean the difference between life and death on the battlefield.

That's precisely why the U.S. military is doing away with its robotic pack mule quadrupeds — because they just make too much noise, possibly giving away troops' positions to the enemy and leaving personnel open to attacks.

Military.com is reporting that its Legged Squad Support System (LS3) — known as robotic pack mules — are being shelved because they're overly noisy in the battlefield. This decision comes despite the $32 million contract between the Pentagon's Defense Advanced Research Projects Agency and Google's Boston Dynamics for the quadruped technology, as reported by the website.

LS3's point is to lighten the load on troops by carrying 400-plus pounds of weight, but the fact that they're too noisy almost makes them a detriment in some ways.

"As Marines were using it, there was the challenge of seeing the potential possibility because of the limitations of the robot itself," Kyle Olson, a spokesperson for the Marine Corps warfighting lab, told Military.com. "They took it as it was: a loud robot that's going to give away their position."

Military.com reports that noise has always been an Achilles heel for Boston Dynamics' robotic quadrupeds. Supporting that suggestion is the company's BigDog quadruped, which was developed before the LS3 and included a two-stroke go-kart engine, warning that the next evolving model would need to be quieter in movement and be able to resist gunfire better as well.

It appears that the technology still has a ways to go if it's going to be deployed again.

You can see the LS3 out in the field in action below.