The Life Cycle of a Frog: A Pond-Side Guide for Curious Kids

Few things in British nature have the drama of a frog’s life. It starts as a blob of jelly, spends months as a swimming comma with a tail, then grows legs, loses the tail and walks out of the pond as something completely different.

Children find this fascinating, and it’s easy to see why. It’s the closest thing most of us will see to a real-life transformation story, and it happens in garden ponds and puddles across the country every spring.

This guide covers each stage of the common frog’s life cycle, what to look for, and a few outdoor activities that go with it.

Meet the common frog

The frog you’re most likely to find in the UK is the common frog, Rana temporaria. According to Froglife, the amphibian conservation charity, it’s found throughout Britain and Ireland, wherever there’s a suitable breeding pond nearby.

Adults are usually olive-green or brown, with a dark “mask” behind the eye and stripes on the back legs. Froglife also points out they can be yellow, pink, red or even black, which tends to surprise anyone who thought frogs came in one colour.

Read next: our guide to pond dipping

Stage 1: Frogspawn

The cycle starts in late winter or early spring, when adult frogs leave their winter shelters and head for the pond. Froglife notes that spawn can appear from January in south-west England, and later further north.

Frogspawn is laid in clumps, and Froglife says a single “raft” can hold up to 2,000 eggs. Each black dot sits inside a clear jelly capsule about a centimetre across, which protects the egg and keeps it buoyant.

Why so many eggs? Frogs lay the eggs and don’t stick around to look after the eggs. Only a small fraction survive. The rest become lunch for newts, fish, beetles and birds.

A quick way to tell frog from toad, as Surrey Wildlife Trust explains:

• Frogspawn is laid in clumps, usually in shallow water like your pond in a forest school area at school.
• Toadspawn is laid in long strings, like a jelly necklace, usually in deeper water.
• Newts lay single eggs, which means you are less likely to spot these in your school setting or out and about on wildlife walks.

Stage 2: Tadpoles

Depending on the weather, tadpoles hatch two to four weeks after the spawn is laid. At first they hang around the remains of the jelly, which they eat, before swimming off to graze on algae.

Young tadpoles breathe through gills and look like little more than a head with a tail. Common frog tadpoles start out black, then develop gold or bronze speckles as they grow, which is one way to tell them apart from toad tadpoles, which stay black.

This is the longest stage, and the one children can watch change week by week. A pond visit every few days turns into a running commentary on who has grown the most. We’ve known children name their favourite tadpoles… but whether they remember which one is which next time is debatable!

Stage 3: Legs appear

Back legs come first. Froglife gives a timeline of around 16 weeks before the back legs start to grow, though warm weather speeds things up and cold weather slows them down.

Front legs follow, and the tadpole’s body changes on the inside too. The gills are replaced by lungs, which is why you’ll start to see tadpoles nipping up to the surface for air.

The diet shifts as well. Older tadpoles start eating small invertebrates rather than just algae.

Stage 4: Froglets

Once the tail has been fully absorbed, the young frog leaves the water as a froglet. Froglife says this usually happens in early summer, though some stragglers don’t make it out until September.

Froglets are tiny, often no bigger than a fingernail, and easy to tread on. If you’re near a pond in June or July, it’s a good idea to walk carefully through long grass and watch your step near the water’s edge!

Stage 5: Adult frog

The froglet spends the next couple of years growing (yes, years!). Froglife says common frogs reach breeding age at two to three years old, at which point they return to a pond to spawn and the whole cycle starts again.

Outside the breeding season, adults live in damp grass, log piles and compost heaps, feeding at night on slugs, snails, worms and insects. In winter they shelter under stones, in compost heaps or in the mud at the bottom of ponds.

You might see them in places you wouldn’t expect, quite far from what you think of as the nearest water source (although there normally is water close by).

Watching, not collecting

When we ran forest school, the most common question at the pond was, “Can I take some home?” It’s an understandable one, but no – don’t take spawn, tadpoles or frogs home.

Surrey Wildlife Trust advises against moving spawn or tadpoles between ponds, because it can spread amphibian diseases and invasive pond plants. That includes the well-meaning rescue of spawn from a drying puddle.

A few habits we recommend for pond visits:

• Look, sketch and photograph rather than scoop.
• If you do net a tadpole for a closer look, use a white tray of pond water and return it to the same spot within a few minutes – check out our guide to pond dipping for tips on equipment and process.
• Wash your hands after touching pond water.
• Keep a pond diary with the date, weather and what you saw, so you can compare week to week – this is great to have up in your forest school area on a wipeable whiteboard.

Outdoor activities to go with the frog life cycle

The frog life cycle is part of the National Curriculum. In Year 5, the science programme of study asks pupils to describe the differences in the life cycles of a mammal, an amphibian, an insect and a bird. Younger children meet the idea that animals have offspring that grow into adults in Year 2.

Here are some ideas that work outdoors, at a pond or away from one:

• Life cycle stick art: arrange sticks, leaves and pebbles on the ground in a circle to show each stage, then photograph it.
• Tadpole tally: count how many tadpoles have back legs on each visit and plot it on a simple chart (links to maths).
• Frog jumps: measure how far children can leap from a crouch, then compare with the fact that frogs can jump many times their body length (links to PE, or outdoor education).
• Spot the difference: compare frog and toad spawn using photos, then go and look. It will help to know already if you have frogs or toads on the premises, because looking and not finding anything can be disappointing.
• Build a log pile: give adult frogs somewhere damp to shelter near the pond.

If you don’t have a pond, it’s worth knowing that frogs are quick to find new ones. A small wildlife pond in a school or garden can attract spawn within a year or two, without anyone needing to move it there. Could you raise the funds for a small pond? You’d have to do the appropriate risk assessment – our local primary school had a raised, brick-surround pond with wire grill over the top, for example.

A quick summary

For anyone who wants the short version, here’s the life cycle of a frog in five steps:

• Spawn: clumps of up to 2,000 eggs in jelly, laid from late winter
• Tadpole: hatches after two to four weeks and breathes through gills
• Tadpole with legs: back legs, then front legs, as lungs develop
• Froglet: tail absorbed, leaves the water in early summer
• Adult frog: ready to breed at two to three years old

Then the frogs head back to the pond, and the children get to watch it all over again next spring.