Autumn warming may explain a decline in Western butterfly populations. One species, the western monarch, has declined 99.99% since the 1980s.

Birds can learn to recognize fast and flashy butterflies they've failed to catch in the past—as well as similar-looking species—research finds.

Recent freezing weather in Texas likely means monarch butterfly numbers will drop again this year.

Harvard researchers develop in vitro method for probing what colors an insect sees.

The stench was once thought to originate from plants, but scientists have now pin-pointed its true origin.

Insects are plentiful and inexpensive. Even when children aren't attending school in person, they can learn from the encounters they have with insects outside.

Milkweed is key to monarch butterflies' life cycle. But adding other flowering plants may help monarchs more than milkweed alone.

After mating, some male butterflies seal their mate's genitalia. But females have evolved ways of fighting back or getting around the "mating plug."

Can a plan that brings together government and private landowners create enough habitat for monarch butterflies?

Loss of milkweed is the most likely reason for the incredible loss of monarchs, a new study of 1.4 million butterflies shows.