After the conditioning, lambs were fed grain or food with tannins or oxalates and then allowed to choose the three medicines. The treatment animals preferred to eat the specific compound known to rectify the state of malaise induced by the food previously ingested. However, control animals did not change their pattern of use of the medicines, irrespective of the food consumed before the choice. Other ruminants learn to self-medicate against gastrointestinal parasites by increasing consumption of plant secondary compounds with antiparasitic actions. Standard laboratory cages prevent mice from performing several natural behaviours for which they are highly motivated. As a consequence, laboratory mice sometimes develop abnormal behaviours indicative of emotional disorders such as depression and anxiety. To improve welfare, these cages are sometimes enriched with items such as nesting material, shelters and running wheels. Sherwin and Olsson tested whether such enrichment influenced the consumption of Midazolam, a drug widely used to treat anxiety in humans. Mice in standard cages, standard cages but with unpredictable husbandry, or enriched cages, were given a choice of drinking either non-drugged water or a solution of the Midazolam. Mice in the standard and unpredictable cages drank a greater proportion of the anxiolytic solution than mice from enriched cages, presumably because they had been experiencing greater anxiety. Early studies indicated that autoimmune (MRL/lpr) mice readily consume solutions with cyclophosphamide, an immunosuppressive drug that prevents inflammatory damage to internal organs. However, further studies provided contradictory evidence. During the cold and rainy seasons, the crested porcupines (Hystrix cristata) in Central Italy tend to become infected by seven different species of ectoparasites and seven different species of endoparasites. During this time, it is observed that these porcupine populations actively sought out a rather large variety of medicinal plants, mostly with antiparasitic properties, to consume. When ingested, these plants appeared to be relieving the symptoms of the infections, such as inflammation. Cats About 70% of domestic cats are especially attracted to, and affected by the plant Nepeta cataria, otherwise known as catnip. Wild cats, including tigers, are also affected, but with unknown percentage. The first reaction of cats is to sniff. Then, they lick and sometimes chew the plant and after that rub against it, with their cheeks and the whole body by rolling over. If cats consume concentrated extract of the plant, they quickly show signs of over-excitement such as violent twitching, profuse salivation and sexual arousal. The reaction