Also, during his interview, Krasinski made a dark joke about how the alien invasion in "A Quiet Place" was like releasing "wolves in [a] daycare center." Despite their savagery, though, the aliens in the movie aren't just ravenous beasts gorging themselves on human flesh for the sake of survival. They actually have a very sophisticated way of communicating with one another. This isn't just a fan theory, either. Ethan Van Der Ryn and Erik Aadahl outright said so during an Inverse interview.
Much like whales or bats, the creatures use echolocation to "see" and, more frighteningly, hunt. They even have a specific, shrill cry which they screech when they move in to attack their prey. This particular sound signals any other nearby creatures to go into attack mode as well (ironically, this shriek eventually becomes their downfall when a feedback loop of the noise is recorded and weaponized against them).
Lastly — although it's only hinted at on a newspaper clipping which briefly flashes across the screen for a few seconds — is the fact that these creatures can and seemingly do manipulate the electromagnetic spectrum to help themselves hunt. Aadahl confirms that "when they come into a room, the lights will flicker or when they appear on the security monitor, [the monitor will] fritz."
