Why did my microwave let out a spark of fire?

Question

I was heating up some mixed veggies for my bird, and put the veggies in for nine seconds.

When it reached around 4 or 3, I saw a spark of fire and stopped the microwave immediately and took the veggies out.

Some of them were burnt

What caused this, and can I feed the unburnt ones to my bird?

Answer 1

did you have some metal foil in there?  Or a twist tie?

Metal causes local overheating and sparks.

You can eat the vegs if you want, they are still good.

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