Having a well ventilated cricket container is essential for keeping healthy live crickets as excess moisture build up can cause many problems. Not only can it destroy your egg cartons but it can also cause your crickets to die. Too much moisture in your cricket container will also attract other insects such as flies and can lead to mould.
The best way to avoid moisture building up is to have an open air container however if this isn't an option for you then you should try to use a lid made of metal fly-screen mesh which you can easily make at home. One way to do this is by building a wooden frame to go around the top of your box and stapling or gluing mesh tightly to it like in the picture below.
Many people poke or drill small air holes in their cricket container lid but this does not allow for enough airflow through out the box. A good rule to go by is that at least 80% of your containers lid should allow for easy airflow into your container. We often see people drilling a few fist sized air holes and covering them with mesh but as stated earlier this will not be good enough if you plan on keeping large amounts of crickets. As shown below, a lid made from metal fly-screen mesh is the best option as it contains your crickets, keeps other unwanted insects out and allows for maximum amount of ventilation.