“Strings of pearls” (arrow and upper inset), whose pearls are up to three millimeters in diameter, were found where SM1 Euryarchaea live in close association with bacteria in the cold sulfidic streams of Germany’s Sippenauer Moor. Part of a pearl (lower inset) reveals colonies of microscopic spherical SM1 surrounded by filamentous bacteria. Credit: Moissl-Eichinger group