Animals in Costa Rica
The animals you are most likely to see always and everywhere are Ants (Hormigas) of every size and character. Ants in Costa Rica represent an estimated 25% of the terrestrial animal biomass.
Ants are diligent workers and can lift several times their own body weight. Even more amazing is their highly developed social organization. Their states are super-organisms where the individual is just a tiny part of the whole body. Colonies of ants can sometimes consist of millions of individuals. To communicate between themselves they use scented chemicals, known as pheromones.
Leaf cutter Ants
Leaf cutter ants (Zompopos) certainly look cute when you see them in long lines, carrying pieces of flowers and leaves. The ants can lift 10 times their own body weight. In a garden you nevertheless don't want them as they can do great damage to your flowers and crop. However, leaf cutter ants are gardeners themselves: they don't eat the plant materials, instead they bring it to their underground gardens to cultivate a special, bread like fungus which they consume.
The mounds of leaf cutter ants can grow to a considerable size with several million of members. The nests are complex, high tech systems with ventilation and intelligent facility management. Their highly organized societies are the largest and most complex on earth - next to humans.
Army Ants (Limpiadores) constantly undertake raids in the jungle, killing and taking home insects and small animals. Their main prey are the nests of other ants whose eggs and larvae they steal to feed on their own offspring. Motmots, Anis and other birds take advantage by following the swarm and picking off insects that try to escape.
Army ants don't build nests, they bivouac for a night to several weeks in hollow logs or underground. The ants are almost blind, instead they rely on their sense of smell.
Should army ants visit your house consider yourself lucky as they will clean it from scorpions, ants and cockroaches. Therefore the Costa Ricans call them Limpiadores, which means Cleaners in English.
These wasps had built their nest right at the side of my bedroom window. Coincidentally the army ants showed up and helped me to get rid of it. The job kept them busy for 2 days.
A perfect example of an animal / plant symbiosis is the bullhorn acacia, a small tree which provides housing for the acacia ants. The ants in turn protect it against herbivorous animals. The aggressive red ants live in the hollow bullhorn-shaped thorns and stems of the tree and swarm out at any movement. They kill insects like crickets that try to eat the leaves, or sting mammals like goats or humans getting in touch with the plant. They even prune back vines that try to grow on their tree. The acacia in turn rewards the ants by producing nectar which they eat.
This is no wasp nest, it's the nest of termites. Their colonies comprise from a couple of hundred up to several million of individuals, relying only on one sole reproductive queen. These queens have the longest life span of all insects: up to 50 years.
In the tropics termites are a constant threat to houses and other constructions. Besides their favourite dish - wood - they also devour books (without even reading them!), eat your natural fibre clothes, and other delicacies at your home.
Termites aren't really ants, instead they are closely related to cockroaches. In fact they are highly specialized wood-eating cockroaches.