Marilyn Klein, aged 9, of Cleveland, Ohio for her question:

How do frogs and toads breathe in the mud in the winter?

Any time is a good time to watch a toad. If you are very lucky, you may get a view of him going to bed for the winter. He is one fellow who can really dig a hole and pull It in after him. His winter home is a foot or so underground. And Mr. Toad digs down and fills up the top of his tunnel with loose dirt.

He goes down backwards, using his hind feet to do the digging. He ‑uses has front legs to pry himself down. The dirt he digs falls in on top of him as he squeezes down, When satisfied, he squats, wearing his usual broad grim. He is below frost level and his snug little hole is dark and comfortable.

Some of the green pond frogs bury themselves in the mud under the water. Also do‑ the tadpole of the bullfrog which take about three years to grow into frogs. Other frogs stretch out comfortably in piles of fallen leaves. Others bed down under rocks and stones. The little tree frogs find winter beds in tree trunks and hollow logs.

Frogs and toads are cold blooded animals. That doss not mean that they can stand the cold. Far from it. Their bodies have no way of keeping themselves warm. The only heat they get is from the air around them. And they are lively only when the air is warm. In cold weather they become sluggish. They cannot remain active in the winter.

So they hibernate. They go into a sound slumber far deeper than ordinary sleep. They have spent the last few weeks of fall weather gorging themselves. This gives them an extra layer of fat ‑ all the food they will get until spring. Once settled, they do not move a muscle. The heart beat slows to almost nothing. And the breathing lungs stop altogether.

However, the sleeping beauties do take in a little oxygen. Their wonderful skins can take oxygen directly into the blood. The frogs and tadpoles deep in the pond dissolve free oxygen from the water. Those under logs  in piles of leaves take oxygen from the air through their hides.

But how about the contented toad buried a foot underground? Can he get oxygen down there? Yes, he can. For, strange to spy, the air reaches deep into the ground. It hides in tiny pockets between crumbs of dirt, It gets trapped in cracks and even in the pores of rocks. There is plenty of air for the buried toad in his hole. There is even plenty of air for the mud‑buried frogs and tadpoles down under the pond.