When you first plop into a rice paddy off the bank, you feel like you’ll be sucked in. The mud squishes up be­tween your toes and cov­ers your an­kle; wa­ter sloshes up your calves but your foot con­tin­ues to sink. Then, sud­denly it hits bot­tom, not hard ex­actly, but bouncy-firm. You stop wor­ry­ing about the quag­mire, and start schlurp­ing your foot up and squish­ing it down a lit­tle fur­ther on. The mud oozes be­tween your toes again. It’s slow go­ing for a be­gin­ner, but fun. No one else at the Cen­tral Java field school was a be­gin­ner, of course. They had all grown up in the rice pad­dies and they had the squared-off feet of peo­ple who see shoes as an en­cum­brance. They were there to learn about bugs…