article_snippet: Scientists found the animals’ stress levels - measured by the hormone corticosterone - rose and
article_snippet: Scientists became difficult to manage as Scientists became increasingly isolated .
article_snippet: Scientists found animals that were isolated had higher levels of stress hormones and became difficult to manage.
article_snippet: Scientists found the animals’ stress levels - measured by the hormone corticosterone - rose and Scientists became difficult to manage as Scientists became increasingly isolated.
article_snippet: These stress levels could also lead to sickness and disease, a study by Nottingham Trent University Physiology and Behaviour found.
highlights_snippet: Isolated animals suffer higher stress levels and become harder to manage .
  