To determine which animal has the least variability in their weights based on the given dot plots, we should consider the range of weights for both cats and small dogs.
For cats, the weights range from 9 to 13 pounds. This gives a total range of: \[ 13 - 9 = 4 \text{ pounds} \]
For small dogs, the weights range from 8 to 15 pounds. The total range for small dogs is: \[ 15 - 8 = 7 \text{ pounds} \]
Given that the range for cats (4 pounds) is less than the range for small dogs (7 pounds), we can infer that cats have less variability in their weights compared to small dogs.
Thus, the correct response is:
Cats, because the range of their weights is less than that of small dogs.