Which characteristic of a pet carrier is not ideal for preventing FAS?

The characteristic of having doors that are very small is not ideal for preventing Fear and Stress (FAS) in birds. A small door can create a negative experience when the bird needs to enter or exit the carrier. If the door is too small, it may cause stress during handling or when the pet is being placed in or removed from the carrier. This can lead to apprehension and fear, especially if the bird feels trapped or is unable to see clearly what is on the other side of the door.

In contrast, options like minimizing hanging toys help reduce distractions or obsessions, while a hard-sided carrier provides safety and stability for the bird. Appropriately sized perches allow the bird to settle comfortably within the space. All these factors contribute positively to the overall experience for the pet, while a small door poses potential difficulties and sources of anxiety.