In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Here we sought to generate information with regard to the interictal period in animals with pilocarpine - induced epilepsy .
### Output Text:
Here we sought to generate information with regard to the interictal period in animals with <span class="chemical">pilocarpine</span> - induced epilepsy . 