Letters to the Editor

Readers discuss dark energy, Ötzi’s tattoos and sneaky plant invasions

Readers react to a rare visual disorder, microplastics in arteries and more

Readers discuss accessible images in print and potassium’s climate potential

Readers consider medical privacy, where sharks rank in food webs

Readers discuss Mimas’ hidden ocean and ancient cave art

Readers discuss ancient plagues and a fern’s leaf revival

Readers discuss tardigrades, poison dart frogs and more

Readers discuss cholesterol treatments and AI

Readers discuss quantum gravity and more

Readers discuss grassland conservation and a hummingbird flight trick

Readers discuss marathoners’ myelin, menopausal chimps and more

Readers react to neutron imaging and the expanding definition of loneliness