Flea call-outs in Hertfordshire follow the weather almost perfectly. A run of warm, humid days in July or August — especially after a wet June — and the phone starts ringing with the same story: 'We've been away for a week and come home to itchy ankles.' That isn't a coincidence; it's the flea life cycle responding exactly as you'd predict.
Why summer triggers an explosion
Cat and dog fleas thrive at 21–29°C with humidity above 50%. At those conditions an egg hatches in 2–5 days, and a larva reaches the pupal stage within a fortnight. Pupae can then sit dormant in carpet for months, waiting for vibration and warmth to tell them a host has arrived. Two weeks away on holiday is the perfect trigger — you walk through the door, the pupae detect you, and dozens of fleas emerge within hours.
Where the eggs actually are
Adult fleas live on the pet, but only about 5% of an infestation is on the animal itself. The other 95% — eggs, larvae and pupae — is in the carpet, the pet's bedding, the gaps between floorboards and the soft furnishings the pet sleeps on. That's why treating the pet without treating the home almost never works.
Breaking the cycle
- Keep year-round vet-prescribed flea protection on the pet — supermarket spot-ons are often ineffective against modern flea strains.
- Vacuum thoroughly twice a week through summer, focusing on edges, under furniture and pet sleeping areas; empty the cylinder straight into an outside bin.
- Wash pet bedding at 60°C weekly during peak season.
- For an active infestation, a professional insecticide with an insect growth regulator is the only reliable fix — it kills adults and prevents eggs developing.
If you're being bitten around the ankles, see tiny dark specks on pet bedding that turn red when wet (flea dirt), or notice the cat suddenly scratching, don't wait. Each female lays up to 50 eggs a day in peak conditions — a week's delay genuinely doubles the size of the problem.