Background/Scope
I've lived in my house about 4 years and had a lot of issues with water after heavy rains. The house has some sort of tiling system bringing water to the sump, which keeps the rest of the basement dry but can bring an overwhelming amount of water to the sump after heavy rain. Several years ago this led to an overflow, so I added a second sump pit & pump next to the existing one. This year I still had to add a temporary backup pump to prevent an overflow after a heavy rain.
If region is a factor, the house is in Minnesota, USA, in an area with fairly heavy clay-based soil.
I'm not expecting to solve this entire problem with this question, just hoping to understand a specific aspect of how foundation drainage systems work.
Question
Today it started raining so I went down to make sure the sump pumps were ready. To my surprise, in the standing water beneath the float switch, there was a salamander (roughly 5" long) swimming around. (It was carefully captured and released in a nearby ravine.)
How did it get in? Would there typically be openings in a drain tile system where a small animal could enter?