Instructions
Observe the stray cat as closely as possible. Size is the first giveaway to determining if a cat is a kitten, as well as unopened eyes (less than 7-10 days old) and unable to really stand and walk (less than 2 to 3 weeks old).
Determine how active the cat is. If the stray cat begins to show some confidence in their movement, particularly their exploring, and is becoming extremely active, than it's a good bet they are 5 to 6 weeks old or older.
Examine the teeth. At 7 months, all adult teeth are typically developed. This includes the deciduous incisors, which are the smaller teeth in the front; the deciduous canines, the longer and pointy teeth in the front; and the pre-molars, all of which should have come in by 8 weeks. These are followed by the incisors (anterior teeth), canines (longer teeth), and molars (broad-surfaced teeth).
Check with a veterinarian. Often, a stray cat can appear small, such as the size of a developing kitten, if it is undernourished.
How Do I Tell If a Stray Cat Is Still a Kitten?
The warm weather typically signifies kitten season. This generally leads to an influx of stray kittens. However, it is not always easy to determine if a stray cat is still a kitten. Generally, a kitten is no longer a kitten when it is 8 months old, and they are not fully mature until they are about 2 years old. There are several ways to tell if a stray or feral cat is still a kitten, including by observing their behavior or, once caught, examining their teeth.