We have used a variety of different plastic cages for respirometry experiments and all seem to work well. Most commonly, I have used Lexan (polycarbonate) caging (typical of many rat or mouse cages). Lexan sheets can be cut to fit as a lid and holes drilled for the incurrent and excurrent air streams. The lid can be sealed using vacuum grease or can be fitted with strips of window or door jam material to eliminate leak. 

Lexan is clear (and stays clear over time) such that you can easily visualize the animal. In addition, it is very hard and not likely to be chewed through by rodents. The cages come in a variety of sizes thus facilitates the correct 'fit' for the animal being tested. And finally, these cages are amenable to rough handling and cleaning. They can even be autoclaved. 

Dear Ashadee,

there is a book called "Measuring Metabolic Rates: A Manual for Scientists" by John R. B. Lighton. You should read it. You can get it on his RG page (https://www.researchgate.net/profile/John_Lighton).

If I remember right, he also published a paper on different materials and their ability of absorbing and releasing different gases.

I hope I coud help.

Best regards,

Chris

Thank you for your answers, they have both been very useful to me.

See E. Don Stevens (1992) "Use of plastic materials in oxygen-measuring systems" in Journal of Applied Physiology

Thanks Paul. Useful paper!