Terrible thing was occured with my Nep!

[eboat]

Hi all,
Yesterday i found many debris of pitchers were eatten by something and from my observed every pitchers had feeding insects(from my feeding) were bitten. At first i think it's cause of snail but it's too fast and selectively to eat the insects inside the pitcher(leafs and stem are safety, no plant relocated). May it be rat? What do you thing(or suggest me)?

Sample of pitchers N. Exotica lady (left) and N. ampullaria (right).

Zoom in



Another plant in nearly place are safety.
viking

Smiling viking

N. Mastersiana

and their feeds

N. truncata

N. mirabilis (Wistuba)

N. Hookeriana

N. ampullaria before pass away

Best regards, eboat