Picking up mice

Learn why & how to use refined methods to pick up mice.

Why should I use refined handling?

Animal Welfare

Scientific Quality

Ease of Handling

Job Satisfaction

Strong evidence indicates that it is beneficial to animal welfare & scientific to picking up mice with refined handling methods (i.e., tunnel handling or cupping) rather than by the tail. Picking mice up by the tail – even for only 2s at cage change – causes negative effects.

Tunnel handling simply involves guiding mice into a tunnel to pick them up. They can then be tipped out backward and scruffed for procedures, as needed. The benefits of tunnel handling remain even if mice are then given injections, have blood drawn, or undergo gas anesthesia. Cupping involves picking mice up with cupped hands, it does not require any new equipment, but does require a bit more training of mice.

What is the evidence for this?

There have been 19 publications supporting the benefits of refined handling improving welfare & scientific quality including:

  • Reducing anxiety as measured by elevated plus maze, social novelty test, open field test, and light-dark box test (shown in 10 papers including Hurst & West 2010)
  • Reducing depressive-like behavior as measured by sucrose reward, resilience to negative events (Clarkson et al. 2018, 2020), forced swim test and burrowing test (Sensini et al. 2020)
  • Reducing chronic stress as measured by adrenal gland size (Clarkson et al. 2020)
  • Increasing test reliability (Hurst & West, 2017)
  • Improving physiological parameters such as improving glucose tolerance & reducing blood glucose & corticosterone (Ghosal et al. 2015; Ono et al. 2016)
  • Increasing voluntary interaction with the handler (shown in 10 papers including Hurst & West 2010)
  • Improving breeding as measured by larger pups (0.75g), more pups born (1), weaned (1.5 ), and longer breeding productive lifespan (20%; Hull et al., In Preparation).

For extensive details on the evidence base for refined handling including a printable table of each study’s key findings & methods see NC3Rs mouse handling research summary.

Common concerns

Will this take longer for husbandry & procedures?

  • Even brief tunnel handling during cage change is sufficient to deliver the positive benefits (Gouveia & Hurst 2019).
  • Once staff are adequately trained husbandry and procedures do NOT take any longer.

What if I have to then restrain mice by the tail or perform aversive procedures?

The benefits of refined handling persist even after standard procedures such as:

  • Scruff or tail restraint (Hurst & West 2010; Roughan & Sevenoaks 2018; Gouveia & Hurst 2019; Henderson et al., 2020)
  • Subcutaneous or intraperitoneal injection (Gouveia & Hurst, 2019; Henderson et al. 2020)
  • Anesthesia (Henderson et al. 2020 )
  • Oral gavage (Nakamura & Suzuki, 2018)

Do I need home cage tunnels?

Home cage tunnels are not necessary to gain benefits from tunnel handling. However, they are beneficial as they provide enrichment, decrease training time as the mice are already familiar with the tunnel, and support biosecurity. Note: to prevent cage leaks from home cage tunnels be sure to place the tunnel parallel along the edge of the cage. 

Where can I purchase tunnels?

You can get tunnels from vendors such as Datesand, Braintree, IPS, LBS, SerLab, etc. or from independent providers. 

What size and material of tunnels should I get?

Tunnels should be appropriate for the size of the cage. Not sure where to start? At some institutions, 3.5 inch square tunnels work great as they can’t get improperly wedged in the cages and can provide an area for a breeding dam to pull up her pups in case of a flood.

If you already use cardboard tunnels those can work. However, if getting new tunnels, clear plastic is recommended to allow for mouse visualization for health inspection in the tunnel and make it easy to slide the mouse out backwards.

What about biosecurity?

Tunnel handling has successfully been used in BSL2 and BSL3 laboratories and immune-compromised mice. 

Are there strain & sex differences?

Thus far refined handling has been beneficial for all strains tested and both sexes (though males of some strains may take a bit longer to train). Strains tested thus far include BALB/c, CD1s, C57BL/6, DBA/2, and ICGN.  These methods were actually developed for handling wild-caught mice

For answers to more frequently asked questions check out the FAQ page on the NC3Rs website: https://www.nc3rs.org.uk/mouse-handling-faqs

How to pick up a mouse using non-aversive handling

For more detailed instruction and for details on cup handling please see training videos on the NC3Rs website: https://www.nc3rs.org.uk/video-clips.

Tips for switching an entire institution to non-aversive handling

  • Curate & identify champions for non-aversive handling from husbandry & scientific staff
  • Get high-level support from management/regulatory bodies (IACUC, etc.)
  • Consider rolling out tunnel handling in stages to address feedback/concerns by personnel type (husbandry versus clinical), project, research group, animal room, etc.
    • Similarly, it may work first to get veterinarian/administration support operations/husbandry support, and then scientific staff.
  • Order adequate supplies
  • Provide training on evidence base & methods
    • Consider bringing in an external expert
  • Track & address concerns, issues, & acceptance

For more details & tips see NC3Rs tips for implementation.

More Resources

For even more extensive information on non-aversive handling of mice, please visit NC3Rs’ How To Pick-Up A Mouse Hub. Their resources include video tutorials, webinar, how-to videos, poster, a practical guide to implementation, a summary of the evidence base, and answers to frequently asked questions.

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