The ball shaped cat toy - thing:1704548 - when printed with PLA and empty, bounced well. However it was fragile and easily broken. Here are two sturdier balls composed of 8 identical sections. In one the sections contain a distorted hexagon held in place by 4 rods; in the other a central point is connected to 6 rods. The balls were printed in PLA and in GP3D "FLEX" and bouncing comparisons made. OpenSCAD code is included.

MakerBot

MakerBot Replicator (5th Generation)

Yes

No

0.2 mm

25%

The following post :
https://www.3dhubs.com/talk/thread/flexible-filament-fiasco
suggests using GP3D flexible filament with a PLA raft. This is easily done with a smart extruder + and worked flawlessly. The raft margin was increased to 8 mm and the filament was changed from PLA to GP3D FLEX when the raft was about half constructed.

These sturdier balls, when printed with PLA, are quite rigid. They do bounce on hard surfaces but noisely. Balls printed with GP3D FLEX bounce well on hard surfaces but not noticeably better than the PLA ones. However they make little noise and their bounce is similar to that of a rubber ball. The cat_toy - thing:1704548 - with its thinner connectors, was printed in GP3D FLEX. The print was easily distorted; not so fragile as the PLA one, and bounceable to a degree. The ball with hexagons was the best bouncer.