In optimum conditions, how long does it take a cat flea to develop from egg to adult?

• A. 45 days
• B. 15 days
• C. 2 months
• D. 3 months

Answer: (B)

Flea development from egg to adult is fastest when conditions are warm and humid, since warmth and moisture speed up the growth through the four life stages: egg, larva, pupa, and adult. Under optimum conditions this entire cycle typically takes about two weeks, around 12–15 days, so 15 days is the best fit among the options. The longer times (45 days, 2 months, 3 months) would occur only if conditions are less favorable—cooler temperatures, lower humidity, or dry environments—slowing or delaying development. In real-world settings, you’ll see some variation, but the two-week range is the standard expectation for optimum conditions.