Try to stick to one Petpetpet species! Unless you would rather have a variety of Petpetpets out on your Habitarium farm, it might prove to be easier to manage with just a single Petpetpet species. By this I don’t mean the Petpetpet type (Soldier/Worker/Nester), what I’m referring to is to the Mootix/Larnikin/Pinchit species. This is more easily achievable during the higher levels. As always, do also keep in mind that workers yield the most EXP per second - so if you're still undecided as to whether or not to focus on harvesting or nesting, I would suggest sticking to majority of your farm to hold workers, and only a handful of Soldiers/Nesters - possibly 3-5 of each depending on your style of play. Additionally, my recommendation would be to upgrade your Petpetpets soon as you are allowed to. Although yes, it is a very minor increase in their attributes, it is a worthwhile investment in the long run. They stay upgraded as long as you’re using the same Petpetpet species so once you’ve upgraded them for the first time, rest assured, they’ll forever stay at that upgrade level!