Philosopher Jean-Jacques Rousseau might have been onto something when he defined happiness as “a good bank account, a good cook and a good digestion.”

I guess two out of three ain’t bad! After a two-week vacation in Italy and France (and a few stormy days stuck in Falmouth to boot), I can count my blessings to have the two latter, even if the former took a hit.

It was the international Slow Food conference that brought me to Italy to explore the pleasures of food and the concepts of good, clean and fair food. My time overseas was all about food and taste; however, it’s the next stages of consumption that now have me ruminating.

From beginning to end, digestion is not just an in and out affair. How we bring food into our bodies varies from the simple to the sublime. Humans are known as ingestive feeders, because we take in food through our mouths. Compare that to others.

Beware of absorptive feeders, including the parasitic tapeworm, which take in nutrients directly though their body walls while living off other organisms. Fear not the filter feeders; bivalves and others that collect food by filtering it out of water sucked in through a siphoning mechanism.

Get the lowdown on substrate feeders, which include earthworms and termites. They eat the material that they burrow through. And, of course, it is the fluid feeders that really suck. Aphids and other fluid feeders obtain nutrients by piercing their food and sucking in fluids.

Once food gets into the system, enjoyment of it varies by species. Not all animals experience the same gratification of food as we humans do, while others might experience it even more! While all animals have some sort of chemical sensors to assess food, only vertebrates have tongues (and thus taste buds).

When it comes to buds, some are more endowed than others. Carnivores generally have the fewest taste buds, while herbivores fare better. On the light side in the taste bud department are chickens, which have about 30 taste buds. Humans come in somewhere in the middle of the heap, with 10,000 taste buds each, while pigs have 15,000 and cows 25,000. At the top of the taste bud pile are catfish, which can have up to 175,000 taste buds per individual!

But I digress. (Or is it digest?)

Digestion provides food for thought for both the epicurean and the biologist. The human digestive system is familiar to most of us. We are considered monogastric, characterized by one simple stomach and possessing upper and lower teeth, which is often, but not always, indicative of an omnivorous lifestyle. Herbivorous ruminants differ because they have a stomach with four compartments and are known for their cud-chewing habits and lack of upper front teeth.

Birds have no teeth at all and don’t chew. Instead, they have a crop where food is stored, soaked and softened, and a gizzard equipped to grind and pulverize their victuals. There are some exceptions, such as owls which lack a crop, and some specialists which bring their digestion to impressive levels. Wild turkeys can pulverize walnuts, and a shrike can fully digest a mouse in three hours!

Which brings me back to slow food. Whether you pulverize and gulp your food or savor it, poet Mary Webb probably summed it up best for all creatures under the sun in one neat little stanza:

“Give me good digestion, Lord,

And something to digest;

But where and how that something comes

I leave to Thee, who knoweth best.”

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.