Bedding Options and Which to Choose (detailed)?

With so many options, it can be difficult to decide what to use.
When choosing an appropriate bedding you want something that allows for;

1. Natural behaviours such as foraging, tunnelling and digging

- Feeding your rats by scattering their food and ruffling it up into your rats bedding a few times a week can be a great way to increase enrichment by allowing expression of natural behaviors which increases quality of life, reduces stress, and can improve temperament as a result.

2. Ammonia neutralization and absorption

- Between a rat's sensitive airways and mycoplasma; ammonia control is critical to their respiratory health. Ammonia levels being too high can lead to respiratory issues and permanent respiratory damage. The thing is, this damage can take several months to show, so by the time you've noticed it's typically too late.

- It’s important to stay away from things that include added scents as this will irritate respiratory tracts and possibly have negative reactions with ammonia in rat urine; and/or bicarbonate of soda (baking soda) as this is a potential danger as it causes a reaction in the stomach that creates carbon dioxide gas (this builds up and causes blockages and ruptures the intestinal tract; which is why bicarbonate of soda is commonly used in rat poisons.)

( positive + ) ( negative - )

Kiln Dried Pine
+ affordable
+ ammonia absorption
+ can help reduce smell
+ changed once or twice weekly (depending on the number of rats)
allows foraging and burrowing

Hemp, Aspen and Flax
+ on par with kiln dried pine
+ hemp is the better option for those with allergies
+optimal tunnelling/burrowing (holds shape well)
- more expensive / harder to find depending on your area

Compressed Wood / Pine Pellets +
+ great for litter box use
+ neutralizes ammonia
+ good absorption
+ allows foraging
- may be expensive (if using in the whole cage)
- heavy when moist
- becomes dusty
- not conductive to burrowing or tunnelling

Coco Peat
+ great for enrichment
+ allows for tunnelling, burrowing and foraging
+ absorbs and neutralizes ammonia
+ can be paired with a “clean up crew” (such as springtails) for bioactivity
- must be kept moist
- not great for overly humid environments

Hay
+ good for nesting material
+ great for foraging
- can be dusty (get good quality hay)
- soils easily
- needs to be changed frequently to prevent ammonia build up

Fleece
- needs to be changed daily to prevent ammonia build up
- fleece has a non-wick layer that needs to be broken into
- does not neutralize ammonia
- requires washing in pet safe detergents to prevent respiratory issues
- not conductive to enrichment (no tunnelling/burrowing)

Shredded Paper / Yesterday’s News
+ paper towel is OK for nesting material
- needs to be changed frequently
- gets overly saturated by liquids easily
- does not neutralize ammonia

Carefresh
+ allows for burrowing and foraging
- gets overly saturated by liquids easily
- does not neutralize ammonia well
- expensive
- needs to be changed frequently to prevent respiration issues

Corn Cob
- grows mould when moist
- needs to be changed frequently

Source 1: Comparative Analysis of Ammonia Levels in Wood Pulp, Corn Cob, Aspen and News Paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3966270/...

Source 2: Fleece is pretty, but doesn’t work https://www.myratfriends.com/.../Fleece-Not-the-Best...

Source 3: Comparative Analysis of Ammonia Levels in CAREfresh, Pine, Corn Cob, News Paper, Maple/Beech/Poplar, Alpha Cellulose https://www.semanticscholar.org/.../da2e2ff611acf8e2ea44a...

Source 4: Pine Efficiency in Rearing Hanwoo Cattle https://www.ncbi.nlm.nih.gov/pubmed/32054214

Source 5: Evaluation of Cage Micro-Environment on Different Substrates:
https://www.ncbi.nlm.nih.gov/pubmed/15264763

Source 6: Importance of burrowing, climbing and standing upright for laboratory rats
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4929907/

Source 7: Differences in anticipatory behaviour between rats housed in standard versus semi naturalistic laboratory environments
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0147595