Whilst long hot days are great for swimming and sunbathing and ripening your tomatoes, they also bring in the flies attracted by food and other smells.
Any pets requiring toilet material will generally create more smells and attract more flies in summer. Whether you have a kitten or puppy, or the kids have a rabbit or guinea pigs, long hot days will increase smells from their toilet and bedding, while open windows and doors will let those smells dissipate further and faster. This can mean you need to clean and change pet litter more often which is a chore no-one in the family enjoys; and you'll also find yourself spending more on pet litter as you go through it quicker.
One of the best solutions available is a 100% natural New Zealand zeolite product from a South Waikato quarry, that is exported around the world and sold across NZ. Kritter Litter is an environmentally friendly pet litter that does a great job and then can be spread on garden flower beds or used with potting mix. Kritter Litter acts fast and has triple benefits of high absorption like a sponge, high adsorption like a magnet, and neutralisation of odours (through what is called cation exchange). The end result is that the ammonium smell from urine (and other smells) is absorbed, and the litter takes up the largest possible volume of moisture, reducing the frequency of changing the litter.
Kritter Litter is sold through the SPCA across New Zealand as an effective, environmentally friendly Kiwi solution to pet smells. Give it a try, you'll notice the difference.