Carnivores live on the energy of herbivores or other animals and they are facing other challenges. Meat is one of the main protein and fat - compounds that has high energy and can be broken down easily. Carnivores’ alimentary tract are shorter compared with herbivores, this shows that they need less efforts at releasing energy and nutrition in food. However, they cause other price, one of the most obvious is that they need to catch and kill their preys. These all are quite high compared with investment for herbivores of finding out their food. In addition, meals are not so frequent, the whole season may pass if their main prey is not able for some carnivores.