It is important for us to understand what capillary action is. Capillary action takes place in nature too and is an important natural process for the sustenance of life. The best way to understand the capillary action is to study the plants which pull up water from the soil.
When we water the plants, the soil absorbs the water downwards and then the plant absorbs the water upwards. The spoil getting absorbed into the ground is a natural process and it happens because of gravity. However, the plant absorbing water from the ground is an action against the gravity of the earth. For example, when you put a sponge on a small puddle of water, you will notice that the entire water is absorbed by the sponge. However, the surface of the sponge is larger than the surface of the water that is being absorbed.
Hydrology explains the process where the water molecules are attracted to the soil particles. Capillary action is the reason why the ground water moves from wet regions into the dry areas.
There are several such examples that can be studied within nature. A capillary tube is also helpful to understand the process. One can see through the glass as to how it is taking place. A surface tension area is created within the tube in the shape of a concave index and it causes enough pressure so that the water is absorbed upwards into the tube. Several life processes takes place because of the presence of capillary action.