Investigation tends to conflict with it in older animals, causing them to separate. Other signs of this behavior are Walking or running together. Lying down, sleeping and getting up together. The giving of care or attention is highly developed in dogs along certain special lines. The tendency toward nest building is rather weak.
Most dogs make use of shelters already provided, or enlarge holes already made.
Grooming is likewise rather poorly developed, consisting mostly of the cleaning of very young puppies by the mother. Adults scratch themselves, but rarely lick their fur, and there is almost never mutual grooming between adults. Feeding the young, on the other hand, is highly developed. The mothers not only nurse their young but may vomit food which they have chewed and swallowed themselves. Under the proper feeding conditions, adults of both sexes may provide food for the young and the habit of burying or catching food is frequently seen.