Final answer:
The correct tag question to add to "A barking dog seldom bites" is "does it?", which makes the sentence "A barking dog seldom bites, does it?" Avoiding comma splices involves properly joining or separating independent clauses in a sentence.
Step-by-step explanation:
The sentence "A barking dog seldom bites" can be turned into a question with a tag by adding a short question at the end that expects confirmation of the statement. For this sentence, the correct tag to add would be "does it?" making the complete sentence: "A barking dog seldom bites, does it?". This is because the main sentence is positive, so the tag needs to be negative; and since the sentence refers to "a dog" which is singular, we use "does" for the auxiliary verb.
Comma splices are a common grammar issue where two independent clauses are incorrectly joined by just a comma without a coordinating conjunction. In the example given, "The rabbit darted out of the shadows. A flash of movement. The dog lunged and strained at the leash," avoiding a comma splice would involve either separating the clauses with a period or semicolon, or using a coordinating conjunction.