Sam, whose knees were tucked under his chin. Ashley looked thoughtfully at her own knees, probably wondering how it would feel if they bent backward.
âAnd bats have been around for 50 million years,â Dr. Rhodes went on. âWe know that from finding fossils that old. But most of all, I want you to remember that bats are intelligent creatures and tremendously useful ecologically. If there are 400,000 bats flying out of Carlsbad Cavern every night eating bugs, can you imagine how many tons of bugs that makes in a month? In a year?
Thatâs a tremendous help to farmers.â
âHow much can each bat eat?â Jack asked.
âConsidering the size of a bat, quite a lot. A nursing female will leave her baby tucked nice and warm with the other pups in the âbat nursery,â then fly out into the night to eat her entire body weightâabout 12 or 13 gramsâin insects. Then sheâll return to her baby, nurse it again, and maybe fly out a second time in a single night to eat that many bugs all over again. Then back to her baby. She never leaves her baby for long. Sheâs a gentle, caring mother.â
Sam, whoâd seemed fascinated by Dr. Rhodesâs lesson, suddenly looked as though he were about to cry. Maybe it was the mention of âa gentle, caring mother,â which Sam didnât have. Steven must have noticed Samâs sad expression too, because he stood up and said, âI guess weâd better get going. I told the kids Iâd take them into the cavern. Sammyâs really anxious to see Left Hand Tunnel.â
âLeft Hand Tunnel? Two different species of bats live there,â Dr. Rhodes said, âthe cave myotis and the fringed myotis. Both species are quite rare. Weâve counted only 354 of the cave myotis and only 12 of the fringed myotis.â
Well, Jack thought, at least that particular tunnel wouldnât be teeming with countless thousands of bats. He felt a little relieved.
âI hope I get to see those rare bats,â Steven told her. âIâm really anxious to shoot some pictures like the ones you just showed us.â
âSteven is a photographer,â Olivia explained.
âOh.â Dr. Rhodes hesitated, then said, âWell, you understand, Mr. Landon, that youâll have to use infrared film in the caves.â
âUhâ¦no! I knew I couldnât use the flash attachment when the bats were flying out of the cavern because it interferes with their echolocation systemâtheir sonar.
But I figured that when they werenât flying, when theyâre just hanging in the caves, I could use my regular flash attachment with fast film.â
âUh-uh.â Dr. Rhodes shook her head. âThe light from a flash attachment, or any kind of light at all, really bothers the bats. Thatâs why we keep the lighting in the Big Room quite low, and in Left Hand Tunnel thereâs no light at all. Youâll have to use infrared film and an infrared filter on your flash.â
Steven looked crestfallen. âI donât have any of that with me. Butâdo you think I can buy these things in the city of Carlsbad? Would a photo store carry them?â
âIâm sure it would.â
âThen Iâll just have to drive back to Carlsbad,â Steven said. âRight now.â
âDa-ad!â Ashley complained, drawing it out into two syllables. âI thought you were going to take us through the cavern.â
âLeft Hand T-T-Tunnel,â Sammy agreed, nodding.
Carefully, favoring her sore ankle, Dr. Rhodes got to her feet before she told them, âYour dad couldnât take you through Left Hand Tunnel by himselfâyou have to sign up to be part of a tour group. Letâs see, what time is it? You might be able to hook up with a tour, but youâll need an adult with you. Kids under 16 arenât allowed to tour the cavern without a parent or guardian.â
All their plans seemed