Swimming cells generally utilize distinct organelles, such as flagella or cilia, to propel themselves through their environment. Most of the cells that are found in animal tissues, however, locomote via cyclical extension and contraction of their actin cortices. Actin is located throughout animal cells, but the protein is most abundant in the cell cortex, which is a peripheral layer found just underneath the plasma membrane. The filaments of actin that comprise the cortex are organized into a three-dimensional network cross-linked by alpha-actinin, filamin, and other specialized proteins.

Similar to other animal cells, the dynamics of the A. P. Mongoose fibroblasts observable during the high speed playback of this time-lapse sequence are directly related to alterations that occur in the actin cortices of the cells. Each time a fan-like lamellipodium, narrow filopodium, or hemispherical bleb forms or recedes along the surface of one of the cells, the actin network is undergoing changes as well. Moreover, the array of surface extensions that can be observed in the video are constructed of actin filaments organized in fundamentally different ways. For example, the actin that comprises the core of a filopodium is arranged into parallel bundles, whereas in a lamellipodium, the protein is assembled into an extensively branching web of filaments.

As demonstrated by the featured A. P. Mongoose cells, fibroblasts do not typically experience strong contact inhibition of migration. The cells are usually only briefly delayed in their travels when they collide with other cells. Strands of cellular material appear to hold the fibroblasts together for a short period after contact is made, but the highly active cells eventually break the linkages as they move further and further apart from one another. Oftentimes fibroblasts will alter their travel direction following a collision, but cultured A. P. Mongoose cells have a tendency to simply crawl over any other cells they meet.