It never hurts to have a hide. That said of my adult animals only about ten percent have hides. They are all in clear containers. The animals that have hides are only ones that will not eat without one. All my babies start out with hides and most will continue to have hides up until they hit around 800 grams depending on container size. With experience you learn to tell when an animal absolutely needs a hide. I do not use tanks but it would be my guess that if you are using one you would always need to provide hides because of the height of the tank. If you are trying to save money hides can made from a lot of the things that end up in the trash. I use empty yogurt cups and food containers for babies. Sub adults and males will get sectioned milk jugs. These things, even if you buy them, are the cheapest part of the endeavor. It is food that can become expensive quick.