AALAS LAT Certification — 100 Verified
Practice Questions with answers
Section 1: Animal Husbandry, Health &
Welfare (Q1–40)
1. What is the recommended temperature range for a standard conventional rodent
room?
A) 64–79°F (18–26°C)
B) 72–78°F (22–25.5°C)
C) 60–65°F (15–18°C)
D) 80–85°F (27–29°C)
Answer: A
Rationale: The Guide recommends 64–79°F for most common laboratory species. The wider
range accommodates species variation .
2. Relative humidity in animal rooms should be maintained between:
A) 20–40%
B) 30–70%
C) 50–80%
D) 10–25%
Answer: B
Rationale: The Guide states 30–70% is acceptable. Extremes can cause respiratory issues or
fungal growth .
3. Which bedding type is most likely to cause respiratory irritation in rodents?
A) Aspen shavings
B) Corncob
C) Softwood (pine/cedar)
D) Paper-based
Answer: C
Rationale: Softwoods contain aromatic hydrocarbons (phenols) that induce liver enzymes
and respiratory irritation .
,4. How often should autoclaved water bottles be changed for a mouse in a static
microisolator cage?
A) Every 3 days
B) Every 7 days
C) Every 14 days
D) Only when empty
Answer: B
Rationale: Typical facility SOPs change bottles weekly to prevent bacterial biofilm, even if
not empty .
5. What is the minimum cage floor space for a single 25 g mouse (according to the Guide)?
A) 6 in² (39 cm²)
B) 12 in² (77 cm²)
C) 15 in² (97 cm²)
D) 25 in² (161 cm²)
Answer: B
Rationale: Guide Table 3.1: up to 25 g mouse = ≥12 in²; 25–30 g = ≥15 in² .
6. Which of the following is an acceptable enrichment for a rabbit?
A) Wire mesh floor
B) Solid rubber chew toy
C) Running wheel
D) Salt lick
Answer: B
Rationale: Rabbits need gnawing enrichment. Wire floors are prohibited. Running wheels
are not species-appropriate; salt licks are for ruminants .
7. A hamster is found with wet tail. What is the primary cause?
A) Salmonella
B) Lawsonia intracellularis
C) Stress and enteritis
D) Ectoparasites
Answer: C
Rationale: Wet tail (proliferative ileitis) is stress-associated, often due to weaning, transport,
or overcrowding .
8. What is the normal gestation period for a rat?
, A) 16–18 days
B) 19–21 days
C) 21–23 days
D) 28–30 days
Answer: C
Rationale: Rats: 21–23 days; mice: 19–21 days; hamsters: 15–18 days .
9. What is the recommended photoperiod (light/dark cycle) for most laboratory rodents?
A) 8 hours light / 16 hours dark
B) 16 hours light / 8 hours dark
C) Continuous light 24 hours
D) 12 hours light / 12 hours dark
Answer: D
Rationale: A 12:12 light/dark cycle is standard for most laboratory rodents as it mimics
natural conditions and helps regulate circadian rhythms .
10. What is the minimum number of air changes per hour (ACH) recommended for animal
housing rooms?
A) 5 ACH
B) 8 ACH
C) 20 ACH
D) 10–15 ACH
Answer: D
Rationale: The Guide recommends a minimum of 10–15 fresh air changes per hour for most
animal housing rooms .
11. How often should cage bedding be changed for mice housed in standard static caging?
A) Once a month
B) Every 2–3 weeks
C) Every day
D) At least once per week or more frequently if soiled
Answer: D
Rationale: Bedding should be changed frequently enough to keep animals clean and dry and
to maintain ammonia levels within acceptable limits. For static cages housing mice, this
typically means at least weekly .
12. Which environmental enrichment is most appropriate for mice?
Practice Questions with answers
Section 1: Animal Husbandry, Health &
Welfare (Q1–40)
1. What is the recommended temperature range for a standard conventional rodent
room?
A) 64–79°F (18–26°C)
B) 72–78°F (22–25.5°C)
C) 60–65°F (15–18°C)
D) 80–85°F (27–29°C)
Answer: A
Rationale: The Guide recommends 64–79°F for most common laboratory species. The wider
range accommodates species variation .
2. Relative humidity in animal rooms should be maintained between:
A) 20–40%
B) 30–70%
C) 50–80%
D) 10–25%
Answer: B
Rationale: The Guide states 30–70% is acceptable. Extremes can cause respiratory issues or
fungal growth .
3. Which bedding type is most likely to cause respiratory irritation in rodents?
A) Aspen shavings
B) Corncob
C) Softwood (pine/cedar)
D) Paper-based
Answer: C
Rationale: Softwoods contain aromatic hydrocarbons (phenols) that induce liver enzymes
and respiratory irritation .
,4. How often should autoclaved water bottles be changed for a mouse in a static
microisolator cage?
A) Every 3 days
B) Every 7 days
C) Every 14 days
D) Only when empty
Answer: B
Rationale: Typical facility SOPs change bottles weekly to prevent bacterial biofilm, even if
not empty .
5. What is the minimum cage floor space for a single 25 g mouse (according to the Guide)?
A) 6 in² (39 cm²)
B) 12 in² (77 cm²)
C) 15 in² (97 cm²)
D) 25 in² (161 cm²)
Answer: B
Rationale: Guide Table 3.1: up to 25 g mouse = ≥12 in²; 25–30 g = ≥15 in² .
6. Which of the following is an acceptable enrichment for a rabbit?
A) Wire mesh floor
B) Solid rubber chew toy
C) Running wheel
D) Salt lick
Answer: B
Rationale: Rabbits need gnawing enrichment. Wire floors are prohibited. Running wheels
are not species-appropriate; salt licks are for ruminants .
7. A hamster is found with wet tail. What is the primary cause?
A) Salmonella
B) Lawsonia intracellularis
C) Stress and enteritis
D) Ectoparasites
Answer: C
Rationale: Wet tail (proliferative ileitis) is stress-associated, often due to weaning, transport,
or overcrowding .
8. What is the normal gestation period for a rat?
, A) 16–18 days
B) 19–21 days
C) 21–23 days
D) 28–30 days
Answer: C
Rationale: Rats: 21–23 days; mice: 19–21 days; hamsters: 15–18 days .
9. What is the recommended photoperiod (light/dark cycle) for most laboratory rodents?
A) 8 hours light / 16 hours dark
B) 16 hours light / 8 hours dark
C) Continuous light 24 hours
D) 12 hours light / 12 hours dark
Answer: D
Rationale: A 12:12 light/dark cycle is standard for most laboratory rodents as it mimics
natural conditions and helps regulate circadian rhythms .
10. What is the minimum number of air changes per hour (ACH) recommended for animal
housing rooms?
A) 5 ACH
B) 8 ACH
C) 20 ACH
D) 10–15 ACH
Answer: D
Rationale: The Guide recommends a minimum of 10–15 fresh air changes per hour for most
animal housing rooms .
11. How often should cage bedding be changed for mice housed in standard static caging?
A) Once a month
B) Every 2–3 weeks
C) Every day
D) At least once per week or more frequently if soiled
Answer: D
Rationale: Bedding should be changed frequently enough to keep animals clean and dry and
to maintain ammonia levels within acceptable limits. For static cages housing mice, this
typically means at least weekly .
12. Which environmental enrichment is most appropriate for mice?
