Ants are a crucial part of nature. Among other roles, ants ventilate the soil, spread seeds, break down organic material, create habitat for other animals and form an essential part of the food chain.
  Estimating ant numbers and mass provides an important baseline for monitoring ant populations amid worrying environmental changes. There are more than 15,700 named species and subspecies of ants, and many others are not yet named by science. Ants’ high degree of social organization has enabled them to colonize nearly all ecosystems and regions around the globe.
  The significant presence of ants has prompted many naturalists to think about their exact number on Earth. But these were educated guesses. Systematic, evidence-based estimates have been lacking. The research done by a Czech institution involved an analysis of 489 studies of ant populations conducted by fellow ant scientists from around the world. This included non-English literature in Spanish, French, German, Russian, Mandarin and Portuguese. Research spanned all continents and significant habitats, including forests, deserts, grasslands and cities. They used standardized methods for collecting and counting ants such as pitfall traps. As you can imagine, this is often boring work.
  From all this, they now estimate there are approximately 20 quadrillion ants on Earth. This figure, though conservative, is between two and 20 times higher than previous estimates. The previous figures employed a “top-down” approach by assuming ants comprise about 1 % of the world’s estimated insect population. In contrast, their “bottom-up” estimate is more reliable because it uses data on ants observed directly in the field and makes fewer assumptions.
  The next step was to work out how much all these ants weighed. The mass of organisms is typically measured in terms of their carbon makeup. We estimated that 20 quadrillion average-sized ants correspond to a dry weight or “biomass” of approximately 11 million metric tons of carbon. This is more than the combined biomass of wild birds and mammals – about 20 % of total human biomass.
  Carbon makes up about half the dry weight of an ant. If the weight of other bodily elements was included, the world’s ants’ total mass would still be higher.
  It was also found ants are distributed unevenly on Earth’s surface. They vary sixfold between habitats and generally peak in the tropics. This underlines the importance of tropical regions in maintaining healthy ant populations. Ants were particularly abundant in forests and, surprisingly, in dry regions, but they become less common in human-made habitats.
  Ants provide vital “ecosystem services” for humans. For instance, a study published August 17, 2022, in the journal Proceedings of the Royal Society B found ants can be more effective than pesticides at helping farmers produce food. They have also developed tight interactions with other organisms — and some species cannot survive without them. For example, some birds rely on ants to flush out their prey. Thousands of plant species feed or house ants in exchange for protection or the spread of their seeds. Many ants are predators, helping to keep populations of other insects in check.
  Alarmingly, global insect numbers are declining due to threats such as habitat destruction and fragmentation, chemical use, invasive species and climate change. Data on insect biodiversity is alarmingly scarce. The team hopes their study provides a baseline for further research to help fill this gap. It’s in humanity’s interest to monitor ant populations. Counting ants is not difficult, and citizen scientists worldwide could help investigate how these important animals are faring at a time of great environmental change.

(A)

James Earl Carter Jr.:

Jimmy Carter, born in rural Georgia to a peanut farmer and businessman father and a mother who was a registered nurse, the future president and humanitarian, grew up in a religious family. Carter attended school in Plains, followed by university study at two Georgia colleges before receiving a Bachelor of Science degree from the United States Naval Academy in 1946. The same year, he married Rosalynn Smith, whom he had known since she was born.
  Upon his father’s death in 1953, Carter returned to Georgia to run the family farm and its supply company. He became active in local political life, earning a seat in the Georgia Senate by 1962. He then announced his candidacy for president in 1974.
  As governor of Georgia, Carter called for an end to segregation in his inaugural address and increased the number of African Americans on the state government staff. He worked to improve the state’s “wasteful government bureaucracy,” he was pro-environment and wanted more school funding.

(B)

Richard Milhouse Nixon:

Richard Nixon was the second of five children born to Frank Nixon, a service station owner and grocer, and Hannah Milhous Nixon. Nixon graduated from Whittier College in California in 1934 and Duke University Law School in Durham, North Carolina, in 1937. Returning to Whittier to practice law, he met Thelma Catherine Ryan, a teacher and amateur actress, after the two were cast in the same play at a local community theatre. The couple married in 1940.
  In 1946, he was elected to the U.S. House of Representatives, defeating five-term liberal Democratic Congressman Jerry Voorhis in a campaign that relied heavily on suggestions about Voorhis’s alleged communist sympathies. Running for re-election in 1948, Nixon entered and won both the Democratic and Republican primaries, thus eliminating the need to participate in the general election. As a member of the House Un-American Activities Committee in 1948–50, he took a leading role in investigating Alger Hiss, a former State Department official accused of spying for the Soviet Union. During the committee hearings, Nixon’s hostile questioning of Hiss did much to make his national reputation as an enthusiastic anti-communist.

(C)

William Jefferson Clinton:

Bill Clinton’s father was a travelling salesman who died in an automobile accident three months before his son was born. His widow, Virginia Dell Blythe, married Roger Clinton, and, despite their unstable union (they divorced and then remarried) and her husband’s alcoholism, her son eventually took his stepfather’s name.
  Clinton enrolled at Georgetown University in Washington, D.C., in 1964 and graduated in 1968 with a degree in international affairs. During his freshman and sophomore years, he was elected student president. During his junior and senior years, he worked as an intern for Sen. J. William Fulbright, the Arkansas Democrat who chaired the U.S. Senate Committee on Foreign Relations. Fulbright was a vocal critic of the Vietnam War, and Clinton, like many young men of his generation, also opposed the war.
  After graduating from Yale University Law School in 1973, Clinton joined the University of Arkansas School of Law faculty, where he taught until 1976. In 1974 he ran unsuccessfully for a seat in the U.S. House of Representatives. In 1975, he married a fellow Yale Law graduate, attorney Hillary Rodham (Hillary Clinton), who thereafter took an active role in his political career.

(D)

Lyndon Baines Johnson:

Lyndon Johnson, the first of five children, was born in south-central Texas to Sam Ealy Johnson, Jr. and Rebekah Baines Johnson, a daughter of state legislator Joseph Baines. Sam Johnson had lost money in cotton speculation, and the family often struggled to make a living. After graduating from high school in 1924, Johnson spent three years in odd jobs before enrolling at Southwest Texas State Teachers College in San Marcos. While pursuing his studies there in 1928–29, he took a teaching job at a predominantly Mexican American school in Cotulla, Texas, where the extreme poverty of his students made a profound impression on him.
  After graduating from college in 1930, Johnson won praise as a teacher of debate and public speaking at Sam Houston High School in Houston. That same year he participated in the congressional campaign of Democrat Richard Kleberg, and upon Kleberg’s election, he accompanied the new congressman to Washington, D.C., in 1931 as his legislative assistant. While in Washington, Johnson worked tirelessly on behalf of Kleberg’s constituents and quickly developed a thorough grasp of congressional politics.