This chapter examines brood site mutualisms, where the pollinators are florivores. In brood site mutualisms, the pollinators are sometimes referred to as nursery pollinators. Here pollination success affects not only plant fitness but also pollinator fitness, and the balance between costs and benefits may be highly variable from place to place and across seasons. There are at least thirteen known nursery pollination systems, and this phenomenon can be divided into three categories. Two of these are relatively unspecialized, where beetle or lepidopteran larvae develop in decomposing flower heads, or where thrips feed in flowers as pollen parasites. The third category is termed “active pollination,” also known as “seed-eating pollination syndrome.” The chapter first considers nursery pollination and thrips as pollen parasites before discussing active pollination, where active pollen transfer occurs and a clear mutualism results.