Pets often tilt their heads when they are trying to listen more attentively or when they are trying to interpret a new or unfamiliar sound. This head tilting behavior helps them adjust the direction of their ears, which can help them locate and understand the source of the sound better. It is also believed that head tilting can help pets see things from a different angle, especially if they are trying to focus on a particular object or person. Overall, head tilting in pets is a common behavior that can help them gather more information about their surroundings.