Cetus Wisps are tiny creatures that can be found on the Plains of Eidolon on Earth. They have light blue energy surrounding them, but due to their small size, they can be tough to see. They can appear during the day or at night so that you can farm them at any time, but they will be a more common spawn at night.
They can be found on the edges of the Gara Toht Lake, just outside the Cetus Gate, and on the banks of the smaller lakes and ponds that cover the Plains. To gather them, all you need to do is find them and move through them, as if they were any other piece of loot. They are used to build Amps, Warframes, and some essential quest items.
What makes Wisps tricky to gather up is that not only are they hard to spot, but they don’t stay around for long after you do find them. When you see one, it is important to grab it fast, as they will float away into the sky and disappear if you can’t get to them in times.
You can purchase Cetus Wisps from The Quills at Cetus for 2000 Standing once you hit the rank of Architect, or from Kakak during the Plague Star event for 750 Standing and 1500 Credits.
If you are searching for Wisps on the Plains, the best tactic is to bring a fast Warframe and rapidly run along the edges of the lakes, moving to a new lake when a full circuit is complete. Wisps will show up as loot on your radar if you use mods like Loot Detector, Animal Instinct, and Thief’s Wit.
Wisps are affected by boosters that increase the number of resources you pick up, and by Smeeta Kavat’s Charm ability. It’s not a good idea to wait for Charm to kick in, however, as the Wisp may disappear before that happens.
On the map above, you will see a good route to take. Use a Warframe like Nehza, Gauss, or Volt to cut down on travel time, and make sure to run entirely around each lake. When you are done, return to Cetus through the gate, then you can load back in to reset the Wisps.