Buckles

 Penelope is obsessed with with buckles.  She enjoys trying to buckle her high chair, and sometimes she gets part of it correctly into the slot.

 See, look how happy she is!

 She tries to buckle the "travel" high chair.  

And recently, she has learned how to unbuckle her carseat "armpit buckle" and wiggle her arms out--no matter how tightly we strap her down.  She still wiggles out!  She also tries to buckle her stroller, but no pic of that.