Category: Feeding Devices

Feeding Experimentation Device (FED) part 2: new design and code

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The Feeding Experimentation Device (FED) is a free, open-source system for measuring food intake in rodents. FED uses an Arduino processor, a stepper motor, an infrared beam detector, and an SD card to record time-stamps of 20mg pellets eaten by singly housed rodents. FED is powered by a battery, which allows it to be placed in colony caging or within other experimental equipment. The battery lasts ~5 days on a charge, providing uninterrupted feeding records over this duration.  The electronics for building each FED cost around $150USD, and the 3d printed parts cost between $20 and $400, depending on access to 3D printers and desired print quality.

The Kravitz lab has published a large update of their Feeding Experimentation Device (FED) to their Github site (, including updated 3D design files that print more easily and updates to the code to dispense pellets more reliably.  Step-by-step build instructions are available here:

Hao Chen lab, UTHSC – openBehavior repository

The openBehavior github repository from Hao Chen’s lab at UTHSC aims to establish a computing platform for rodent behavior research using the Raspberry Pi computer. They have buillt several devices for conducting operant conditioning and monitoring enviornmental data.

The operant licking device can be placed in a standard rat home cage and can run fixed ratio, various ratio, or progressive ratio schedules. A preprint describing this project, including data on sucrose vs water intake is available. Detailed instructions for making the device is also provided.

The environment sensor can record the temperature, humidity, barometric pressure, and illumination at fixed time intervals and automatically transfer the data to a remote server.

There is also a standard alone RFID reader for the EM4100 implantable glass chips, a motion sensor addon for standard operant chambers, and several other devices.

Feeding Experimentation Device (FED)

WP_20160320_003Feeding Experimentation Device (FED) is a home cage-compatible feeding system that measures food intake with high accuracy and temporal resolution. FED offers a low-cost alternative (~$350) to commercial feeders, with the convenience of use in tradition colony rack caging.

In their 2016 paper, “Feeding Experimentation Device (FED): A flexible open-source device for measuring feeding behavior,” Katrina P. Nguyen, Timothy J. O’Neal, Olurotimi A. Bolonduro, Elecia White, and Alexxai V. Kravitz validate the reliability of food delivery and precise measurement of feeding behavior provided by FED, as well as, demonstrate the application of FED in an experiment examining light and dark-cycle feeding trends, and another measuring optogenetically-evoked feeding.


KravitzLab has shared the Arduino scripts for controlling FED, as well as, the python code used to analyze the feeding data collected by FED on the KravitzLab Github. Additionally, build instructions and power considerations are detailed on the FED Wiki page and 3D Design Files provided through TinkerCAD.

Nguyen, Katrina; O’Neal, Timothy; Bolonduro, Olurotimi; White, Elecia; Kravitz, Alexxai (2016). Feeding Experimentation Device (FED): A flexible open-source device for measuring feeding behavior. J Neurosci Methods, 267:108-14.