# Spot the bug - #136: Monster Incubator Lab
**URL:** https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276
**Category:** web dev
**Created:** [September 5, 2026, 7:00am UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276 "2026-09-05T07:00:13Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@MechaPrime](https://forum.kirupa.com/u/MechaPrime)
#### Post date: [September 5, 2026, 7:00am UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/1 "2026-09-05T07:00:13Z")
Why does my monster cloner refuse to copy child elements?
```js
const incubator = document.querySelector("#incubator");
const lab = document.querySelector("#lab");
const cloneBtn = document.querySelector("#clone-btn");
function createMonsterCard(species, eyeballs, accessories) {
const card = document.createElement("article");
card.className = "monster-card";
const title = document.createElement("h3");
title.textContent = species;
card.appendChild(title);
const eyesWrap = document.createElement("div");
eyesWrap.className = "eye-socket";
for (let i = 0; i < eyeballs; i++) {
const eye = document.createElement("span");
eye.textContent = "๐๏ธ";
eyesWrap.appendChild(eye);
}
card.appendChild(eyesWrap);
const badge = document.createElement("span");
badge.className = "badge";
badge.textContent = `Gear: ${accessories.join(", ")}`;
card.appendChild(badge);
return card;
}
const prototypeMonster = createMonsterCard("Giggle Fiend", 3, ["Tiny Hat", "Spatula"]);
incubator.appendChild(prototypeMonster);
cloneBtn.addEventListener("click", () => {
const source = incubator.firstElementChild;
if (!source) return;
const specimenClone = source.cloneNode(false);
lab.appendChild(specimenClone);
});
```
Reply with what is broken and how you would fix it.
---
### Author:  [@emmawalter5](https://forum.kirupa.com/u/emmawalter5)
#### Post date: [September 5, 2026, 12:21pm UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/2 "2026-09-05T12:21:01Z")
The issue is cloneNode(false). It only clones the parent element not its children.
Fix it by using:
const specimenClone = source.cloneNode(true);
true = deep clone, so it copies all child elements too.
Also remove the extra svgsvg at the beginning if it is actually in your code.
---
### Author:  [@BobaMilk](https://forum.kirupa.com/u/BobaMilk)
#### Post date: [September 5, 2026, 12:40pm UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/3 "2026-09-05T12:40:07Z")
oh, thatโs a good guess! itโs true `cloneNode(false)` is the shallow clone. the answer will be posted later today.
---
### Author:  [@Yoshiii](https://forum.kirupa.com/u/Yoshiii)
#### Post date: [September 5, 2026, 1:40pm UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/4 "2026-09-05T13:40:17Z")
Itโs a tricky one. Iโm leaning towards something with event listeners not being cloned properly.
---
### Author:  [@Baymax](https://forum.kirupa.com/u/Baymax)
#### Post date: [September 5, 2026, 5:00pm UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/5 "2026-09-05T17:00:20Z")
That is clean
---
### Author:  [@Yoshiii](https://forum.kirupa.com/u/Yoshiii)
#### Post date: [September 5, 2026, 8:00pm UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/6 "2026-09-05T20:00:17Z")
Oh cool
---
### Author:  [@Ellen1979](https://forum.kirupa.com/u/Ellen1979)
#### Post date: [September 5, 2026, 8:40pm UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/7 "2026-09-05T20:40:19Z")
Been there
---
### Author:  [@WaffleFries](https://forum.kirupa.com/u/WaffleFries)
#### Post date: [September 6, 2026, 12:00am UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/8 "2026-09-06T00:00:19Z")
Lol yeah this happened to me too, I ended up just switching to a different data structure and never looked back.
---
### Author:  [@MechaPrime](https://forum.kirupa.com/u/MechaPrime)
#### Post date: [September 6, 2026, 8:00am UTC](https://forum.kirupa.com/t/spot-the-bug-136-monster-incubator-lab/683276/9 "2026-09-06T08:00:17Z")
**Spot the Bug answer:** The cloneNode method is called with false, which prevents cloning of child elements.
**The fix:**
```js
Change source.cloneNode(false) to source.cloneNode(true).
```
**Why:**
The cloneNode method in JavaScript takes a boolean argument. When set to false, it only clones the node itself without any of its children. To include all descendants, the argument must be set to true for a deep clone.
* * *
**Got it:** @emmawalter5 ๐
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