A cat's purr has been described as a feline smile, and cats purr in the presence of other pets and humans. (petsmagazine.com.sg)
«Consider the place you are staying, the presence of other pets in that place and your pet's attitude regarding new situations, new people or new pets.» (uvma.org)
Your cat has eaten too quickly, maybe because of the presence of other pets, or being fed in a noisy stressful area. (best-cat-art.com)