Our muscovys were hand raised from a day old and were the most calm and affectionate of all the breeds we've raised. During their adolescence they can be quite elusive and a little jumpy, however, I have found them to mellow very much as they mature. Ours love to be patted, follow closely and are the most trainable of all breeds. Muscovys are the only duck breed I've come across that will let you pet them like a dog (except while broody). They are extremely good foragers and very quiet- though they still express themselves with eager heavy breathing/panting/hissing noises or song-like calls. Very good pets and adaptable with other animals, however, can be quite sassy and domineering in a mixed flock (with other breeds).
