help with not only a captive animal's mental health, but the animal's physical health. For example, food can be hidden and spread cross an enclosure making the animal actively search for it. Other common manipulable tactile objects include rubber toys stuffed with treats. Instead of providing the food directly, foraging devices are useful in increasing the amount of searching and foraging of food, comparable to the amount of time they would spend in the wild. Most food-based enrichment occurs in the context of searching for food, such as cracking open a nut or digging holes in tree trunks for worms. Structural enrichment Structural Enrichment is when objects are added to an enclosure to mimic an animal's natural habitat. These objects can be switched out occasionally or kept permanently. The environment of captive animals should be switched frequently since their environment in the wild would bring on new objects and exploration. Research into what constitutes the most beneficial and appropriate forms of enrichment must be used when considering the provision of enrichment options, especially for species where natural-like settings may be difficult to achieve. The animal should never become too familiar with their environment because that can cause boredom, no stimulation or stereotypical behavior. Examples of this could be swings or climbing structures. Stones have also been shown to encourage exploratory behavior in Japanese macaques. Interaction with the stones exhibited behaviors such as gathering, rolling in hands, rubbing, and carrying. Other common forms include cardboard, forage, and even the texture of the food (i.e. hard, smooth, cold, warm). Olfactory enrichment Olfactory enrichment can stimulate naturalistic behavior, enhance exploration, and reduce inactive behaviors. Olfactory enrichment can be utilized by itself, paired with novel toys, or paired with food-based enrichment. This type of enrichment is most commonly used with species that commonly utilize their olfactory senses in the wild. Although highly beneficial, it is important for researchers to analyze the long-term effects of certain odors on captive animals. Odors can be scattered on a novel toy such as a ball or semi-randomly throughout an enclosure. Various forms of odors can include catnip, odor of conspecific, perfume, feces of a prey species, or spices. Cognitive enrichment Cognitive enrichment is defined as, improving animal welfare by providing opportunities for captive animals to use cognitive skills for problem solving and providing limited control over some aspects of its environment. In the wild, animals deal with ecological