Erroneous pellet counting error on FED3 feeding monitor

[Mingxuan Lu]

Hello! I used 3-mm small food pellets (each pellet weighs approximately 10–12 mg) for my experiment. Preliminary short-term observation shows the monitor registers an increase of 4–5 pellet counts instantly when mice merely touch the pellet, even when the pellet is not removed or consumed at all. We are confused about the root cause behind this counting artifact and wonder whether switching to larger-sized pellets can resolve this erroneous triggering issue.

[Lex]

Hi Mingxuan,

FED3 was designed for 20mg pellets like F0163 from Bio-Serv:

https://www.bio-serv.com/product/DPP_RGB.html

I suspect that your 10-12mg pellets may be too small for the pellet sensor and it is causing unreliable pellet detection, which FED3 registers as multiple pellets being dropped and removed.  

Can you acquire some 20mg pellets to confirm if that works better?

Best,

-Lex 

On Thu, Jun 4, 2026, 5:16 AM Mingxuan Lu <mingxu...@gmail.com> wrote:

Hello! I used 3-mm small food pellets (each pellet weighs approximately 10–12 mg) for my experiment. Preliminary short-term observation shows the monitor registers an increase of 4–5 pellet counts instantly when mice merely touch the pellet, even when the pellet is not removed or consumed at all. We are confused about the root cause behind this counting artifact and wonder whether switching to larger-sized pellets can resolve this erroneous triggering issue.

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[Mingxuan Lu]

Much appreciated for your advice! Our custom diets vary in ingredient and density, so we will test 4 mm pellets soon. Could you also let me know the maximum allowable pellet diameter for FED3? Many thanks!

[Lex]

You're welcome! I don't know the maximum size, FED3 dispensing was designed for those 20mg pellets so I'd recommend trying to get as close as you can get to that size. 

With custom diets, the texture and crumbliness can also be a factor to consider. Harder pellets will dispense better than soft pellets that might crumble and create dust. 

Good luck with the custom pellets, it sounds interesting!

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