Keller and Marian trained a wide variety of animals, experimenting with shaping behavior using reinforcement. In Marian Breland Bailey's unpublished memoir, "The Animal Company", she wrote of early experimentation with training cockroaches while working with B. F. Skinner on the "Pigeon in a Pelican" (the nickname given to the missile) project for the United States Navy during 1942 in Minneapolis, Minnesota:
Unlike the majority of animal trainers, the staff at ABE used positive reinforcement rather than punishment in behavior shaping. ABE training principles were based on working with and understanding the natural instincts and emotions of an animal, while using reinforcement to shape new behaviors.
Some people questioned the care and treatment of the animals trained and used in acts. ABE was very careful and descriptive in the acts' manuals about the amount of food, exercise, and attention each animal received.