You won't need rocks actually IN the pond for the toads. They're air breathers, and they will prefer to sit in a sheltered, cool area outside the pond during the day. When you initially fill your pond, go ahead and use tap water. The chlorine will evaporate before the toads and frogs find the new pond. But when you need to "top off" the pond, that is add water after some of it has evaporated, you can "age" the water by putting water in a bucket and allowing it to sit out for 24 hours or so before adding it to the pond. That allows time for the chlorine to evaporate. Yes, you are correct. A liner is a strip of (usually) black rubber, very flexible, and can be shaped to the size you want. Mosquito dunks are donut shaped objects that you place in the water to prevent mosquito larvae from hatching. You can find them at any garden center, but if you have a small pump in your pond to keep the water moving, you won't need them. Mosquitos cannot lay their eggs on water that has a current. If you can get at least two feet wide and 12 inches deep on your pond, I think you'll be okay. Remember, the smaller you go, the bigger the water loss due to evaporation, and that will make it harder to maintain a healthy balance for the tads. You will get algae in the pond. Tadpoles eat algae, so if there is none, you can buy algae wafers at pet stores to feed the little guys.

He tells me they are a toad, not a frog, all though I don't know the difference. Check the link below, colokid, as well as this one: How to tell the difference between frogs and toads I have always associated frogs with lakes or ponds, while toads were more of a dry land amphibian, but I think I have been mistaken! I wish I had toads in my garden, but with three mini-Dachshunds and a Shepherd/Malamute mix of my own, plus the neighborhood cats, no such luck. I've never actually seen one around here, but I used to have garter snakes in my garden, but if they are still around, they keep themselves well hidden. :-( Holly Here is a link that might be useful: Frogs vs Toads

It seems dunks aren't entirely safe for birds. I put a very small crumb of a donut into my fantail pigeon's bird bath to keep the mosquitos from breeding while we were on vacation. My son called us while we were in California to say the birds were dying. When we got home 8 out of our 12 pigeons were dead. Our birds also had pigeon waterers to drink from so guess not all of them drank the birdbath water. Mosquitos never get into the waterers, but I had to empty out the birdbaths every few days because of wiggletails in them. I've kept pigeons for almost 30 years and never had anything like this happen. Thought of writing to the company that makes them to inquire to see if pigeons were particularly sensitive to them, but never did. Glad to hear that apparently the amphibians are doing okay with mosquito dunks, just thought I'd pass this along.

A few days/weeks after some heavy rain, you often see hundreds if not thousands of tiny toadlets or froglets metamorphosing and coming out of their pond/puddle all at once. They are probably true toads (genus Anaxyrus) or Spadefoot Toads (genus Scaphiopus). Beyond that, toadlets are hard to identify.