Stupid Question -- Size of a team?

I’ve looked, but I feel like I’m missing something that should be obvious. Is there a limit to how many members can be on a team?

So, there is no rule, just suggestions as to what works best.

We’ve been picking up members as interest grows. It is getting unwieldy. I’d like to field two teams next year if we can, but for now we just have a big team. Just didn’t want to risk disqualification or anything.

It’s really up to you and how you like to work. Most teams have about 3-4 people, but I’ve seen teams with more. As you add more people, division of tasks becomes more important, and it may be difficult to find something for everyone to do. It’s often challenging to have just four people working on the robot at the same time, and you can only have so many programmers.
Base your decision on a design you have in mind (a more complex design may require more team members) and all of your other resources (I.e. how many bots can your club build).