Banana and mango crops sometimes are damaged by these marsupials. Occasionally they are found in bunches of bananas in warehouses and stores in the United Stares, having remained in the bunch when it was shipped from the tropics. Some species of Marmosa may breed throughout the year, while others are seasonal. Litter size is 7-9 in the wild and slightly smaller in captivity. Life expectancy probably is under 1 year in the wild but is about 3 tears in captivity.
Reproductive ability declines in the second year of life.
One male M. robinsoni obtained at an unknown age lived for almost 5 more years, an apparent record longevity. A female Marmosa reportedly had 14 young attached.