The life detector allows you to find animals on your territory. It lets you choose a tile to search and gives you a list of up to 8 creatures whose survival requirements (as shown in the field guide) are being met by that tile. This list is influenced by the weather, indicated in the upper right corner of your screen. Tap the weather icon to toggle through a list of creatures which are extra discoverable at the moment.
Start by tapping the life detector icon to the bottom left of your screen, then choose a magnifier if you have any special ones to choose from. You can scroll through your special magnifiers using the arrows. If you don’t have any, you’ll be using the default one. Next pick a tile where you want to look for animals.
You will see a list of icons showing either mystery creatures or animals you have, and your chances of finding each. If the icon is shimmery with a single ring around it, it’s a species that was unlocked with a special habitat. If it’s shimmery with two rings, there is a legendary creature here.
If you want to search this area, hit the search button. You can’t cancel once you’ve started! The timer starts at 1 minute for the first creature, then 2 minutes, then 4, 6, 8, 11, 14, 16 and so on. This wait time increments per instance of a species that you find in Desertopia. A species can only appear once on any given tile in each skin that it has (mutants and event skin creatures do add to the total number of creatures on a tile). If you find exactly the same animal there several times, it will not increase your next wait time. Your wait time will be determined by the total number of animals you can see with “All Creatures” switched on in your settings. You can watch ads, spend gems, or use a special magnifier to reduce or skip the wait. Each ad will reduce your wait time by one hour.
When the search timer is up, if the discovered animal is a new creature, go find it and tap it! You need to do this to make it appear in your field guide. If you don’t, it will still appear as a mystery icon in your searches even though you already have it.
If you have “Let the cloud track the footprints for you” checked off in the “Search for footprints” screen, a random area will be searched for you if you don’t search somewhere yourself. Using this doesn’t seem to help in finding undiscovered creatures.
As the number of animals on your island will affect your wait time while searching for new animals, you really don’t want a million of them. They will pile up as you try again and again for that elusive [redacted] so you will want to find ways to mediate their numbers.