Here is a rather interesting experiment with animals - no animal was hurt during this experiment :D. Fire ants is a special species which use their claws to grip diverse surfaces, including each other. A certain adhesion can be observed among them due to this characteristic. When they move in large numbers, they seem to flow like fluids.
This film shows how ants behave similarly to the spreading of drops, the capillary rise of menisci, and gravity-driven flow down a wall. By emulating the flow of fluids, ant colonies can remain united under stressful conditions.