What may be important for training a duck to voluntarily enter a crate?

Training a duck to voluntarily enter a crate can be significantly enhanced by the use of a ramp. Ducks, like many birds, are physically adapted to moving in certain ways, and a ramp can make it easier for them to access the crate. It reduces the physical barriers to entry, allowing them to walk up to the crate comfortably rather than having to hop or fly, which may cause stress or hesitation.

The ramp's inclination can be adjusted to suit the duck's abilities, making the crate more inviting. Additionally, ramps can help reinforce positive associations by leading the duck toward a reward or a familiar environment, encouraging them to enter the crate willingly.

While water is a natural and appealing resource for ducks, it may not directly aid in the process of getting them to enter a crate. Instead, it could potentially create distractions. Handles on the crate may improve ease of movement for the handler but do not address the duck's approach to entering. Having another duck could provide companionship and encouragement but does not guarantee that the individual duck will enter the crate on its own. Utilizing a ramp, however, focuses directly on facilitating the physical act of entering the crate, making it an effective training tool.