Bunny ears cactus (Opuntia microdasys) originated in Mexico and is a denizen of arid, desert-like areas. Growing bunny ears cactus is as simple as mimicking its native regional conditions. So if you have a dry, low humidity home and plenty of sunny exposure, bunny ears cactus plant might be the perfect plant for you.
Bunny ears forms a 2 to 3 foot (61-91 cm.) tall plant with a spread of 4 to 5 feet (1- 1.5 m.) in its native habitat. In the home, it is a slow growing plant that will likely reach 2 feet (61 cm.) in height and have about the same width. It makes an excellent container plant with its paired 3 to 6 inch (8-15 cm.) long pads, which start out a rosy red and deepen to bright green.
Source: Gardening Know How