The world of animals is classed as one of the unhappy realms because suffering and ignorance predominate there. Obviously there is a wide range of situations within this realm, as in all the realms. A pampered house pet may know more happiness than many humans. Nevertheless, for most beings in this realm life is uncertain, short and full of struggle. Furthermore, animals have only rudimentary language and cannot learn and discuss spiritual matters as we can in the human world.
The animals constitute the only other realm that is normally visible to our senses. It is worth reflecting on how vastly this kingdom outnumbers the human. Consider the insects and worms in a shovel full of garden soil, or the mosquitoes on a summer night. We may think there are a lot of human beings on this planet, but for all our so-called overpopulation we still constitute a tiny fraction of the number of beings.
Contemplating the animal realm in this way, especially the insects and other small and lowly creatures, can lead us into two important and complementary, reflections. One is the preciousness of a human rebirth, and the other is the terrible nature of samsara.
When thinking about the animal realm, we should also consider that for those currently in an animal rebirth, one of the principal agents of suffering is Man. To much of the animal realm we must appear as terrible demons who inflict the pains of trapping, shooting, mutilating and slaughtering. To counter this, a knowledge of karma and rebirth should lessen our alienation from other beings and rouse compassion to the animals, our fellow travelers on the awful wheel of birth and death.