Materials and Reagents

1. Latex gloves (NIPPON Genetics, catalog number: SLPF-M )
   
2. Filter paper (3 MM CHR) (GE Healthcare, catalog number: 3030-909 )
   
3. Paper towels (KCWW, Kimberly-Clark, catalog number: 47000 )
   
4. Laboratory-bred mice
   Note: For the test, male mice should be used to avoid the effect of the estrous cycle. Mice are housed in groups 3-5 per cage, kept in a room with controlled temperature (~23 °C) and humidity under 12 h light/dark cycle (lights on at 8:30 AM) with ad libitum access to food and water.
   
5. 2,4,5-trimethylthiazole (nTMT) (7.9 M) (Tokyo Chemical Industry, catalog number: T1068 )
   Note: A component of fox feces, TMT (2,5-dihydro-2,4,5-trimethylthiazoline), is known to evoke innate fear responses in rodents (Kobayakawa et al., 2007; Kaneko-Goto et al., 2013). Non-dihydrogenated TMT (nTMT) also induces similar freezing and avoidance responses (Takahashi et al., 2016).
   
6. 70% ethanol
   

Equipment

1. Test cage (31 x 21 x 12.5 cm) (one cage per one mouse)
   
2. Habituation cage with the same size as the test cage (four cages per one mouse)
   
3. Clear acrylic board (which can cover the roof of the test cage)
   
4. Video camera (Sony, catalog number: HDR-CX560V )
   Note: The mouse behavior is recorded under the weak-light condition. This model (Sony Nightshot Camcorder) is equipped with infrared-mode.
   
5. Tripod for camera (SLIK, catalog number: F 740 )
   
6. Red light
   
7. Fume hood
   

Software

1. Microsoft Excel (Microsoft)

Procedure