They’re intelligent and friendly. Why some people think rats are the perfect pet, for fun and comfort.

When Abby Chronister started college six years ago, she found herself struggling with anxiety and depression. After class, she often retreated to her bed. That’s when she adopted her first two rats, Luci and Lena.

“Those little critters are what made me get out of bed, knowing I had those little lives to care for,” the 25-year-old graphic designer from Mission, Kan., said. “They bond with you like a dog does. You might not have the energy to walk a dog, but you can manage to fill a water bottle.”