(domesticated) Animal Years (AY) per year, or simply (domesticated) animal population is a metric to estimate the amount of suffering caused by humans due to use of animals.

It is notable that about 97% of animal years caused by humans for food are attributable to honey.

It is quite surprising, that even before entomophagy (eating insect) becoming worldwide practice, the overwhelming majority of animal life-years caused by humans are attributable to insects (honey bees).

This table does not include farmed marine animals, or for example, silkworms, cochineals, lac bugs, lab animals.

For the quality of life of insects including honey bees see, for example, “How Good or Bad Is the Life of an Insect?” (Simon Knutsson, http://www.simonknutsson.com/how-good-or-bad-is-the-life-of-an-insect)

Note:
Data other than honey bees: FAOSTAT, Live Animals, World, Stocks, 2014 (http://www.fao.org/faostat/en/#data/QA)
“Animals live nes”: “Any other animal grown for meat, eggs, feathers and skins, e.g. ostrich, antelope, deer, reindeer, chamois.”

Data for honey bees:
FAOSTAT, Livestock Primary, World, Production Quantity, Honey, natural, 2014 (http://www.fao.org/faostat/en/#data/QL) : 1,510,566 tonnes

“How much honey does the average worker honey bee make in her lifetime? – 1/12 teaspoon.” (https://www.honey.com/newsroom/press-kits/honey-trivia)

Density of Honey: 1.36 kg/l (https://en.wikipedia.org/wiki/Honey#Nutritional_and_sugar_profile)

Estimated average lifespan of honey bees: 4 months (25-35 days summer, 6-8 months winter)
(Amdam, Gro Vang, and Stig W. Omholt. “The regulatory anatomy of honeybee lifespan.” Journal of Theoretical Biology 216.2 (2002): 209.)

Calculation:
World Honey Production 2014: 1,510,566,000,000 grammes. (1,510,566 tonnes * 1000 * 1000)
One teaspoon: 5mL (metric, https://en.wikipedia.org/wiki/Teaspoon#Metric_teaspoon)
One teaspoon of honey: 6.8 gramme (5mL * 1.36 kg/L)
Honey per honey bee: 0.56666666666667 gramme (6.8 gramme * (1/12))
Honey lifetimes per year: 2,665,704,705,882 (1,510,566,000,000/0.56666666666667)
Honey years per year: 888,568,235,294 (2,665,704,705,882 * (4/12))

Human population: Data for 2014 (in accordance with the FAOSTAT data), 7.21 billion (http://www.wolframalpha.com/input/?i=world+population+2014)

In terms of animal days caused per day, honey is the most harmful animal product per kilogramme. 214,706 days of life is needed for 1 kilogramme of honey. (Average lifespan: 121.66666667 days, Average amount of honey produced per lifespan 0.566666667 gramme)

This number is so huge, consuming 1 kilogramme of honey is equivalent to 9,335 kilogrammes of chicken. (if honey bees and chickens suffer the same amount per day) (animal day footprint of chicken is 23 days, data by Brian Tomasik, http://reducing-suffering.org/how-much-direct-suffering-is-caused-by-various-animal-foods/#Results)

Consumption of 1 kilogramme of honey is equivalent to 180,425 kilogramme of ‘beef’ (under same-suffering/day assumption, ibid.)

I calculated honey bee years caused for honey per year (i.e. population).

The result was quite surprising. Although farmed fishes were not included in the picture, there are about 1 trillion honey bees in the world (889 billion). This far surpasses the total number of other ‘livestock’, 29 billion (FAOSTAT data).

Although farmed fishes were not included, 97% of animal-years caused for food every year is attributable to the production of honey.

1 trillion animals exist due to humans, 97% attributable to honey