Standing before a masterpiece in a hushed museum gallery, most visitors admire the brushwork, the colors, the composition.

Alfred Barr Jr. was the original director of the Museum of Modern Art when it opened in 1929; during his tenure, he lived at this Carnegie Hill co-op.

Art typically seems like a human activity, tied to culture, symbols, and personal expression. Yet a small group of animals has created paintings and designs that sold for surprising sums. Their work ...