The Mimosa species of plants began as a creeping annual plant in Central and South America and is still often used as a ground cover. The Mimosa pudica or Sensitive Plant is the variety most often grown as a houseplant. The Sensitive Plant has prickly delicate branches and feathery fronds that fold inward and droop when they are touched, shaken, or even blown on; these are called seismonic movements. The leaflets of a Sensitive Plant reopen in about half hour but fold up naturally each night. Although fun to watch, the opening and closing of the leaves weakens a Sensitive Plant if it occurs too often. These plants are considered poisonous and should be kept away from pets and children. Read more about common houseplants that are poisonous in Don’t Feed Me to Your Cat: A Guide to Poisonous Houseplants. A Mimosa Pudica may produce tiny pink flowers that resemble little fluffy balls, but this occurs more often when it is planted outdoors than indoors.
It’s very hard to get a Sensitive Plant to bloom indoors. You might try moving your plant outdoors once the temperature is staying above 60 degrees. The bright outdoor light might encourage it to bloom. Also use a fertilizer high in potassium in the spring and summer.
Sensitive Plants are very toxic and should be kept away from animals and small children. I know cats can reach just about anything so here are a couple of ideas how to keep them away from your plants. Cats do not like the smell of citrus so sometimes orange peels in the soil keep them away. Pet Stores sell several products that smell awful to cats that you can spray on your plants. You can plant a pot of Kitty Grass that will attract your cats and keep them away from your other plants.
Mimosa Pudicas need to be pruned on a regular basis to keep their shape. Start cutting back the leggy stems two or three of them at a time. As those start to branch out cut back the other stems. The plant will look full again before you know it.