Variety by Mike McCahill

An urgent sense something grave and damp is creeping up on all these characters, papery though they sometimes appear – carries “The Swarm” some distance further than expected. This viewer will be tuning in again, keen to see whether those Orcas will ever chill out, and if marine biologists and hunky fishermen, like adjacent water signs, are as natural a match as they sound.

IGN by Marya E. Gates

While bogged down with too many characters and often nonsensical science talk, the first two episodes of The Swarm find the terror in the deep blue sea, stoking fear of the unknown and mining the anxiety of ecological collapse with chilling results.

Sioux City Journal by Bruce Miller

How this will ultimately play out depends on “The Swarm’s” ability to embrace a disaster film vibe. So far, it’s a lot of seeking, but little to destroy.

Wall Street Journal by John Anderson

It isn't easy to draw a bead on a new series based on one episode, which was all that was ready to be reviewed. And pilots are always about setting up characters and situations. The former seem likable enough based on our brief acquaintance. And the situation is as follows: Nature is fighting back, and the denizens of the deep are taking no prisoners. It is a provocative if not entirely original idea.

Decider by Joel Keller

The first episode of The Swarm suggests that there will be a lot of throat clearing and not a whole heck of a lot of actual thrills.