One of the tasks that you will need to compete for Sheldra in Bugsnax is to break two Preying Picantises. These are very aggressive, largely Bugsnax that you can find on some raised platforms in the Sizzling Sands area.
Breaking them is actually quite easy, thankfully. Go to the Preying Picantise on the lower platforming and get close enough for him to aggro to you. Back away and lead him off the platform, towards the small pool of water in the center of the area.
You can lead him into the water or the Sodie that will be swimming around will fire water at him. Either way, keep him distracted while his timer runs out, and when it does he will break up into smaller Bugsnax.
The Preying Pircantise on the raised platform is more awkward, as he just does not want to come down. The best solution is to simply leave the area and come back the following day. The first Preying Picantise will have respawned, and you can just lead him to the pond again and repeat the process.
If you want, you can try to catch the Bugsnax that make up the Preying Picantis, but none of them are needed for any quests, and they can all be caught elsewhere in the game.