I'm not a school teacher; ....... but, it's true most sounds bats make during echolocation occur beyond range of human hearing. Our normal (human) hearing range is about 20 Hz to 15-20 kHz, where most bat vocalizations occur in the 9 kHz to to 200 kHz range - so there is some overlap there. Obviously, we can hear bats making many sounds - those made by their claws as they move while at roost or the fluttering sound of their wings, either at roost or in flight. Most humans can hear some of the sounds made when bats are in echolocation mode, and almost anyone with normal hearing, if you describe what to listen for, can hear faint clicks on calm nights while insect-eating bats are nearby and in flight, the 'click sound' being part of the chirps used during echolocation. I don't consider my hearing to be all that sharp, but just last week I did observe some bats clicking as I stood quietly watching them while waiting for my dog to finish his chore in the gloaming. Too, from a short distance, people with normal hearing would have no trouble hearing some of the vocal communication that passes between mother and pup. Al

I think it is perfectly on-topic. Frogs (and toads) are wonderful garden companions and help control the pest population by eating tons of pests. Of course, the downside is that the frogs also might devour some of the beneficial insects too. With rampant flooding all around us, we are getting tons of new wildlife showing up in the yard looking for high ground, food and water. The million frogs that showed up in May laid eggs so we're going to have a billion frogs by the end of the summer. Early in the morning, there's so many frogs in the garden that you have to walk slowly to give them time to jump out of your path. I wish we could train the frogs and toads to sit on top of the porch light and eat all the little pests buzzing around it at night. Like George, I leave little brushy corners (and small flat pans of water in dry years) for the toads. It is impossible to have too many frogs or toads in the garden, except that a lot of snakes come to the garden to eat them, so the population never really gets way out of control.

FWIW, when I moved here in 2004, I couldn't help but notice the occasional native green tree frog harmlessly hopping around. Never a bother, I was happy to let them be as I realized this was their native habitat long before I came along. Then it all suddenly changed violently around 2012, - that's when these glutinous monsters, the CTF's, appeared suddenly. At the same time, the smaller, friendly native green tree frogs disappeared. They disappeared because the huge, vile, ugly CTF's were eating them. I wish I had a $5 bill for every time I saw a CTF in the process of swallowing whole one of the little green guys. It was obnoxious to anyone who saw it, the green frog's head well into the mouth of the much larger CTF's mouth, with the green guy's legs still twitching frantically. They may have but I never saw a green tree frog swallow another frog. One big CTF was photographed after he swallowed an outdoor Christmas light,..his big ugly body lit up a bright red. The population of CTF's exploded drastically while I never saw any more of the green tree frogs. I recall one GW'er telling of discovering a huge CTF swimming around in her toilet bowl. Eventually they were everywhere. My worst confrontation with one of the huge ( too large to hold in one hand ) greasy gluttons was early one morning when I looked in close at one of my large mango leaves that was quivering a bit, only to be shocked when one of the big ugly CTF's sprung off the leaf and splattered on my chest. I looked down right into those big round eyes while he hung on tenasciously,..yeah, got a good look at a CTF that time,...it also confirmed to me that my heart was in good shape ! :o) The CTF's home territory is Cuba, not here. Was so glad to notice them disappearing after I fought them diligently for about 5 years. All my neighbors felt the same,..GOOD RIDDANCE !

I couldn't think of any other factors that might lead to a difference in the ratio. I know it happens with crocodiles and turtles, and that amphibians are linked more closely with reptiles than with other vertebrates. With rising global temperatures there's a concern that crocodiles and turtles may end up "unisexual", or at least highly imbalanced. But I haven't found any studies on similar effects on frogs, only on rate of development. None of those went beyond larval stage to maturity where sexing is possible. Where questions do arise about effects on ratio the only answer seems to be "there is no answer". So for whatever reason, guess you're going to have to get used to summer long frog batchelor parties. Maybe during those sleepless nights you can do a study of them and publish a paper "Temperature effects on frog male/female ratios and resultant sleep deprivation in humans". I'll bet no one else has done that one before, LOL.