Quackoria Play
Candling Room
An egg candling game from a real hatchery job: eggs move past a lamp, you read what the light shows inside each one and drop it in the right tray, through four days of incubation.
Hatcheries candle their eggs, and most people who incubate duck eggs at home learn to do it too: a dark space, a bright lamp, and an egg held against it so the light shows what is happening inside. The Cornell Duck Research Laboratory’s hatching guidance candles at about seven days, to remove eggs that are infertile or have a dead germ, and again at day 25, when the eggs of common breeds move to the hatcher. In between, the picture changes week by week — from a red spider of veins around a dark spot, to an embryo that fills most of the shell, to a large air cell at the blunt end with a duckling moving beneath it.
Candling Room is an egg candling game that puts you at that lamp. Eggs come down a belt, light up as they pass under the lamp, and you have until the dotted line at the bottom of the lamp to decide: Keep, Clear, Dead or Crack. Twelve eggs make a day. Two of the four days — 7 and 25 — are the candling points Cornell’s guidance names; days 14 and 21 are the game’s own checks in between. Each day the belt runs a little faster, and by the last two days a live egg is almost all shadow, so what was obvious on day 7 has to be read from the air cell and a flicker of movement by day 25. Three wrong sorts end the run; five right in a row pays a bonus.
What you are learning to see is real. The blood ring, the clear yolk shadow, the veins, the growing air cell are described by Cornell, Mississippi State Extension, Illinois Extension and Metzer Farms, and the FAQ below quotes them. The speeds and the points are ours.
Sources: Cornell Duck Research Laboratory, hatching duck eggs; Mississippi State Extension, testing incubated eggs; Illinois Extension, candling eggs; Metzer Farms, candling pictures; Metzer Farms, hatching instructions.
How to Play
- Press Candle. Eggs come down the belt and light up as they pass under the lamp; the lowest one is the one you are sorting.
- Look inside. Veins mean a living embryo; a clear egg with only a yolk shadow is infertile; a red ring or a dull mass with no vessels is a dead one. A bright jagged line on the shell is a crack, whatever is inside.
- Sort the lit egg into one of four trays: Keep, Clear, Dead or Crack. Tap the tray, press its number, or move with the arrow keys and press Enter.
- Every egg must be sorted before it reaches the dotted line at the bottom of the lamp. A wrong tray or a missed egg costs one of your three lives.
- Twelve eggs make a day. Then the incubation moves on — day 7, 14, 21, 25 — and what you see inside changes with it.
- Finish day 25 and the good eggs go to the hatcher. The room starts again, faster.
Controls
Desktop
- 1, 2, 3, 4Sort the lowest lit egg into Keep, Clear, Dead or Crack
- Left / Right arrowsMove the tray cursor
- Enter, Space or Down arrowSort into the selected tray
- RRestart from day 7
- MToggle sound
Mobile
- Tap a traySort the lowest egg under the lamp
- Tap the board when pausedCarry on
Gameplay tips
- Check the shell before the inside. A cracked egg can have a living embryo in it and still belongs in the Crack tray — the bright jagged line on the shell is the tell.
- Once the shell is sound, veins decide it. Clean red vessels mean the embryo is alive, whatever else is going on.
- A blood ring is a circle with nothing spreading from it. That is the embryo that died early — the blood drew away from it.
- You cannot sort an egg until it is under the lamp, because you cannot see inside an unlit egg. Wait for the glow.
- Five correct in a row pays a 25-point bonus on top of the 10 each. A steady rhythm beats a fast one.
- Later days are darker inside. On days 21 and 25 the live embryo fills the egg and only the air cell at the blunt end stays bright — watch for movement.
About the game
Candling Room is an egg candling game that turns a real hatchery job into a sorting challenge. Candling is holding a bright light to an egg to see what is inside. Two of the game's four days are the checks hatchery guidance actually names: the Cornell Duck Research Laboratory has you candle at about seven days to remove infertile and dead eggs, and again at day 25, when common duck eggs move to the hatcher and the air cell should fill about a third of the egg. Days 14 and 21 are the game's own intermediate checks, drawn from what Mississippi State Extension describes at two weeks and what Metzer Farms describes late in incubation. What each tray means — spider veins for a living embryo, a clear egg for infertile, a blood ring for an early death — comes from Cornell, Mississippi State Extension, Illinois Extension and Metzer Farms. The belt speed and the point values are game design.
Frequently asked questions
What is candling?
Shining a bright light through an egg to see the contents. Metzer Farms notes the word is old — the light was once a candle. Hatcheries use it to remove infertile and dead eggs so they do not spoil in the incubator.
How do I tell a live egg from a dead one?
Veins. Metzer Farms says the most critical feature is clear, distinct blood vessels; a dead embryo has no clean vessels and looks yellowish instead of vibrant red. Early on, a dead embryo shows as a blood ring — Illinois Extension explains that when the embryo dies the blood draws away from it and forms a ring.
What does an infertile egg look like?
Clear. Mississippi State Extension describes it as a clear egg except for a slight shadow cast by the yolk. Nothing has started to grow.
Why these four days?
Cornell's duck hatching guidance candles at about seven days and again at 25, when eggs transfer to the hatcher. Days 14 and 21 sit between them so the game can show how the view changes as the embryo grows.
What is the air cell for?
It is the pocket at the blunt end that grows as the egg loses moisture. Cornell says it should occupy about one-third of the egg at 25 days in common ducks. Cornell puts the ideal weight loss by then at about 14 percent; Metzer Farms says about 13 percent. Both agree that losing far more or less hurts hatchability.
How long do duck eggs take to hatch?
About 28 days for common breeds such as the Pekin, according to Cornell, and about 35 for Muscovy. Metzer Farms gives mallards around 26.5 to 27 days and Runners about 28.5.
How is the game scored?
Ten points for each correct tray and a 25-point bonus every fifth correct sort in a row. At the end of each day you get 15 points for every life you still have. Three wrong or missed eggs end the run.
Is my best score saved?
Yes, in your own browser.
