Gecko is a reptile that usually moves at night and feeds on insects and other small invertebrates. Their bodies are usually flat, with four legs and a tail.
Rats are also nocturnal mammals, feeding on grains, seeds, insects and other small animals. They usually have long tails and keen sense of hearing and smell.
According to the information you provided, a new shit will be found every night. But based on the existence of excrement, it is not certain whether it is a gecko or a mouse.
In order to determine which animal left the excrement, we can consider the following characteristics:
1. Shape: Gecko's excrement is usually slender, while mouse's excrement is shorter and rounder.
2. Size: Gecko's excrement is usually smaller than that of mice.
3. Color: Gecko's excrement is usually darker, while mouse's excrement is lighter.
4. Location: Geckos usually crawl on walls, ceilings or the ground, while mice move on the ground. So the gecko's excrement may appear in a higher position.
According to these characteristics, we can try to answer your question.
1. If these excrements are slender and dark, and appear in high places such as walls or ceilings, they are probably gecko excrements.
2. If these excrement are short and round, and appear on the ground or at a lower position, it is probably the excrement of rats.
Please note that these characteristics are not absolute, and the final judgment may need to be combined with other factors. If you have more information or photos, you can provide them to us so that we can help you better.