nice. also demos what a great language R is for writing short and sweet code.

The problem description is NOT totally correct. it's not how many rats died. We have a total of 10 rats. That's it. These rats are put on position numbered from 0 to 9, so total 10 rats.
1000 bottles of wine are also numbered from 0 to 999. Then each bottle of wine is polled into the glasses in front of the rats according to the binary representation of the bottle number, that is: if the bottle number has bit 1 for position i (0<=i<=9), then poll wine into the glass of that position.
The numbers we received should be the position number of the rats.

Not an issue.

The description stated length less than 3 should return false, but this is not implemented. Non letters should not be considered

Not an issue. The reason for using the t statistic is in the description (you do not know the population standard deviation, so you need a t statistic). More details for those who are interested can be found in the linked articles. Thank you for the suggestion to use test values from different distributions. I'll consider that.

more sample test to know whether the code is working?

should ask the function to return a tuple with the order swapped

In the intro might be useful to add why the T statistic is used. Most are more familiar with the 2 standard deviation. Also maybe using test values from different distributions e.g poisson or runif to see how skew the CI can be